FTP test failures on centos6

Apparently centos6 is stuck on curl version 7.19, just before
--ssl-reqd turned up in 7.20.  Wow!

Check curl version and select --ssl-reqd for version 7.20+.

getssl

@@ -1115,14 +1115,14 @@ copy_file_to_location() { # copies a file, using scp, sftp or ftp if required.
           SFTP_PORT=":990"
         fi
         # shellcheck disable=SC2086
-        debug curl ${_NOMETER} $FTPS_OPTIONS --ssl-reqd -u "${ftpuser}:${ftppass}" -T "${fromdir}/${fromfile}" "ftps://${ftphost}${SFTP_PORT}/${ftpdirn}/"
+        debug curl ${_NOMETER} $FTPS_OPTIONS "${_CURL_SSL_REQD}" -u "${ftpuser}:${ftppass}" -T "${fromdir}/${fromfile}" "ftps://${ftphost}${SFTP_PORT}/${ftpdirn}/"
         # shellcheck disable=SC2086
-        curl ${_NOMETER} $FTPS_OPTIONS --ssl-reqd -u "${ftpuser}:${ftppass}" -T "${fromdir}/${fromfile}" "ftps://${ftphost}${SFTP_PORT}/${ftpdirn}/"
+        curl ${_NOMETER} $FTPS_OPTIONS "${_CURL_SSL_REQD}" -u "${ftpuser}:${ftppass}" -T "${fromdir}/${fromfile}" "ftps://${ftphost}${SFTP_PORT}/${ftpdirn}/"
       else
         # shellcheck disable=SC2086
-        debug curl ${_NOMETER} $FTPS_OPTIONS --ssl-reqd -u "${ftpuser}:${ftppass}" -T "${fromdir}/${fromfile}" "ftp://${ftphost}${SFTP_PORT}/${ftpdirn}/"
+        debug curl ${_NOMETER} $FTPS_OPTIONS "${_CURL_SSL_REQD}" -u "${ftpuser}:${ftppass}" -T "${fromdir}/${fromfile}" "ftp://${ftphost}${SFTP_PORT}/${ftpdirn}/"
         # shellcheck disable=SC2086
-        curl ${_NOMETER} $FTPS_OPTIONS --ssl-reqd -u "${ftpuser}:${ftppass}" -T "${fromdir}/${fromfile}" "ftp://${ftphost}${SFTP_PORT}/${ftpdirn}/"
+        curl ${_NOMETER} $FTPS_OPTIONS "${_CURL_SSL_REQD}" -u "${ftpuser}:${ftppass}" -T "${fromdir}/${fromfile}" "ftp://${ftphost}${SFTP_PORT}/${ftpdirn}/"
       fi
     else
       if ! mkdir -p "$(dirname "$to")" ; then
@@ -1620,10 +1620,10 @@ for d in "${alldomains[@]}"; do
             if [[ "${to:0:5}" == "ftps:" ]] ; then
               [ -z "$FTP_PORT" ] && SFTP_PORT=":990"
                 # shellcheck disable=SC2086
-                curl ${_NOMETER} $FTPS_OPTIONS --ssl-reqd -u "${ftpuser}:${ftppass}" --silent -Q "DELE /${ftplocn}/${token:?}}" "ftp://${ftphost}${SFTP_PORT}/${ftplocn}/"
+                curl ${_NOMETER} $FTPS_OPTIONS "${_CURL_SSL_REQD}" -u "${ftpuser}:${ftppass}" --silent -Q "DELE /${ftplocn}/${token:?}}" "ftp://${ftphost}${SFTP_PORT}/${ftplocn}/"
             else
                 # shellcheck disable=SC2086
-                curl ${_NOMETER} $FTPS_OPTIONS --ssl-reqd -u "${ftpuser}:${ftppass}" --silent -Q "DELE /${ftplocn}/${token:?}" "ftp://${ftphost}${SFTP_PORT}/${ftplocn}/"
+                curl ${_NOMETER} $FTPS_OPTIONS "${_CURL_SSL_REQD}" -u "${ftpuser}:${ftppass}" --silent -Q "DELE /${ftplocn}/${token:?}" "ftp://${ftphost}${SFTP_PORT}/${ftplocn}/"
             fi
         else
           rm -f "${t_loc:?}/${token:?}"
@@ -3077,6 +3077,12 @@ if check_version "${_CURL_VERSION}" "7.67" ; then
     _NOMETER="--no-progress-meter"
 fi
 
+if check_version "${_CURL_VERSION}" "7.20" ; then
+    _CURL_SSL_REQD="--ssl-reqd"
+else
+    _CURL_SSL_REQD="--ftp-ssl-reqd"
+fi
+
 # Make sure mktemp works before going too far
 MKDIR_TEST_FILE="$(mktemp 2>/dev/null || mktemp -t getssl.XXXXXX)"
 if [ "$MKDIR_TEST_FILE" == "" ]; then