fixing: remove semicolon from the flags (#2717)

* fixing: if (${USE_POSIX_THREAD} ... causes a syntax error, adding
a semicolon to the flags

* Metadata updates for release 8.12.41 (#2718)

* Penmetsaa maven update release 8.12.41 (#2719)

* [maven-release-plugin] prepare release v8.12.41

* [maven-release-plugin] prepare for next development iteration

* Update README.md (#2720)

Co-authored-by: penmetsaa <penmetsaa@google.com>

cpp/CMakeLists.txt

@@ -467,7 +467,7 @@ endif ()
 
 if (${USE_POSIX_THREAD} STREQUAL "ON" OR ((APPLE OR UNIX) AND ${USE_BOOST} STREQUAL "OFF" AND ${USE_STDMUTEX} STREQUAL "OFF"))
   if(CMAKE_USE_PTHREADS_INIT)
-    list (APPEND CMAKE_C_FLAGS "-pthread")
+    set (CMAKE_C_FLAGS "${CMAKE_C_FLAGS} -pthread")
   endif()
   if(CMAKE_THREAD_LIBS_INIT)
     list (APPEND LIBRARY_DEPS ${CMAKE_THREAD_LIBS_INIT})