Remove external plugin support

Jagex has requested I take steps to prevent users from making plugins
which are in violation of the game rules. This limits plugins to the core
plugins.

runelite-client/src/main/java/net/runelite/client/config/RuneLiteConfig.java

@@ -51,18 +51,4 @@ public interface RuneLiteConfig extends Config
 	{
 		return true;
 	}
-
-	@ConfigItem(
-		keyName = "enablePlugins",
-		name = "Enable loading of external plugins",
-		description = "Enable loading of external plugins",
-		confirmationWarining = "WARNING: Using untrusted third party plugins is a SECURITY RISK\n"
-		+ " and can result in loss of YOUR ACCOUNT, and compromise the security\n"
-		+ "of your computer. Are you sure you want to do this?",
-		warnOnEnable = true
-	)
-	default boolean enablePlugins()
-	{
-		return false;
-	}
 }