Set the shared object version (SOVERSION) to only version major.minor

This declares that the library ABI is intended to be backward
compatible to older versions of the same major.minor version.

CMakeLists.txt

@@ -272,7 +272,7 @@ add_library(datachannel SHARED
 	${LIBDATACHANNEL_IMPL_HEADERS})
 set_target_properties(datachannel PROPERTIES
 	VERSION ${PROJECT_VERSION}
-	SOVERSION ${PROJECT_VERSION}
+	SOVERSION ${PROJECT_VERSION_MAJOR}.${PROJECT_VERSION_MINOR}
 	CXX_STANDARD 17
 	CXX_VISIBILITY_PRESET default)
 target_compile_definitions(datachannel PRIVATE RTC_EXPORTS)