Revert "Warn about a comment starting with a comma."

Breaks Jaskier's MPT player.
https://sourceforge.net/p/asap/bugs/32/

This reverts commit 7a666799ac.

source/app.d

@@ -367,11 +367,6 @@ void checkNoExtraCharacters() {
 	switch (line[column]) {
 	case '\t':
 	case ' ':
-		if (pass2) {
-			readSpaces();
-			if (!eol() && line[column] == ',')
-				warning("Comment starts with a comma. Unintended whitespace?");
-		}
 		return;
 	default:
 		throw new AssemblyError("Extra characters on line");