[Commands] Remove #undyeme Command. (#2776)

# Notes
- Removes redundant `#undyeme` command.
- Adds `GetGM()` check to `#undye` so players can't undye other players.

zone/gm_commands/undye.cpp

@@ -3,7 +3,7 @@
 void command_undye(Client *c, const Seperator *sep)
 {
 	auto target = c;
-	if (c->GetTarget() && c->GetTarget()->IsClient()) {
+	if (c->GetTarget() && c->GetTarget()->IsClient() && c->GetGM()) {
 		target = c->GetTarget()->CastToClient();
 	}
 

zone/gm_commands/undyeme.cpp

@@ -1,7 +0,0 @@
-#include "../client.h"
-
-void command_undyeme(Client *c, const Seperator *sep)
-{
-	c->Undye();
-	c->Message(Chat::White, "Undyed armor for yourself.");
-}