- fixed wrong line number in error message

Parser of MAPINFO editor number definitions didn't assign line numbers, so 'Unknown actor class' fatal error displayed some garbage

(cherry picked from commit 751e318c4e)

src/g_doomedmap.cpp

@@ -186,6 +186,7 @@ void FMapInfoParser::ParseDoomEdNums()
 			memset(editem.args, 0, sizeof(editem.args));
 			editem.argsdefined = 0;
 			editem.noskillflags = false;
+			editem.linenum = sc.Line;
 
 			int minargs = 0;
 			int maxargs = 5;