Handle empty strings better.

git-svn-id: http://svn.zoneminder.com/svn/zm/trunk@3311 e3e1d417-86f3-4887-817a-d78f3d33393f

zmconfgen.pl.in

@@ -184,6 +184,7 @@ sub generateConfigSQL
 sub addSlashes
 {
 	my $string = shift;
+    return( "" ) unless $string;
 	$string =~ s|(['"])|\\$1|g;
 	return( $string );
 }