engine: client: GetRefAPI now must return REF_API_VERSION to prevent possible issue when ref library wasn't recompiled on version bump

engine/client/ref_common.c

@@ -425,7 +425,7 @@ static qboolean R_LoadProgs( const char *name )
 	// make local copy of engfuncs to prevent overwrite it with user dll
 	memcpy( &gpEngfuncs, &gEngfuncs, sizeof( gpEngfuncs ));
 
-	if( !GetRefAPI( REF_API_VERSION, &ref.dllFuncs, &gpEngfuncs, &refState ))
+	if( GetRefAPI( REF_API_VERSION, &ref.dllFuncs, &gpEngfuncs, &refState ) != REF_API_VERSION )
 	{
 		COM_FreeLibrary( ref.hInstance );
 		Con_Reportf( "R_LoadProgs: can't init renderer API: wrong version\n" );

engine/ref_api.h

@@ -37,6 +37,7 @@ GNU General Public License for more details.
 // 5. Removed GetSomethingByIndex calls, renderers are supposed to cache pointer values
 //    Removed previously unused calls
 //    Simplified remapping calls
+//    GetRefAPI is now expected to return REF_API_VERSION
 #define REF_API_VERSION 5