togglefloat should only work in dotile mode (thanks to Sander for this hint)

view.c

@@ -202,7 +202,7 @@ restack(void) {
 
 void
 togglefloat(Arg *arg) {
-	if (!sel)
+	if (!sel || arrange == dofloat)
 		return;
 	sel->isfloat = !sel->isfloat;
 	arrange();