Don't error out of Lua parsing when mobjinfo[] isn't a object definition

Source/Core/SRB2/LuaObjectParser.cs

@@ -139,8 +139,7 @@ namespace CodeImp.DoomBuilder.SRB2
                     token = ReadToken();
                     if (token != "=")
                     {
-                        ReportError("Invalid object definition, missing =");
-                        return false;
+                        continue;
                     }
 
                     SkipWhitespace(true);