Typo fix in Source0 url

Signed-off-by: Peter Lemenkov <lemenkov@gmail.com>

el/rtpengine.spec

@@ -6,7 +6,7 @@ Summary:	The Sipwise NGCP rtpengine
 Group:		System Environment/Daemons
 License:	GPLv3
 URL:		https://github.com/sipwise/rtpengine
-Source0:	https://github.com/sipwise/rtpengine/archive/%{version}/%{name}-%{version}.tar.gz
+Source0:	https://github.com/sipwise/rtpengine/archive/mr%{version}/%{name}-%{version}.tar.gz
 Conflicts:	%{name}-kernel < %{version}-%{release}
 
 BuildRequires:	gcc make pkgconfig redhat-rpm-config