fix url opener and make more relaxed

replace the call to open with a call to xdg-open
add the -r flag to xurls to scan regardless of scheme

config.def.h

@@ -375,7 +375,7 @@ static MouseShortcut maltshortcuts[] = {
 
 #if EXTERNALPIPE_PATCH // example command
 static char *openurlcmd[] = { "/bin/sh", "-c",
-	"xurls | dmenu -l 10 -w $WINDOWID | xargs -r open",
+	"xurls -r | dmenu -l 10 -w $WINDOWID | xargs -r xdg-open",
 	"externalpipe", NULL };
 #endif // EXTERNALPIPE_PATCH