Clear MiniPlaceholders on reload and plugin disable

[BlitzOffline]

I've added a clear method to the MiniPlaceholderManager and completely forgot to use it. When the plugin is reloaded or disabled, the old placeholders are not being removed. This shouldn't be a big issue on disable unless people use plugins such as PlugMan but on /chatchat reload this could lead to conflicts and issues.

ChatChat/plugin/src/main/java/at/helpch/chatchat/placeholder/MiniPlaceholderManagerImpl.java

Line 39 in 77e413d

private void clear() {

ChatChat/plugin/src/main/java/at/helpch/chatchat/config/ConfigManager.java

Lines 58 to 59 in 77e413d

	miniPlaceholders();
	miniPlaceholders.placeholders().forEach(placeholder -> plugin.miniPlaceholdersManager().addPlaceholder(placeholder));