externalpluginmanager: Fix development mode after #2815

runelite-client/src/main/java/net/runelite/client/plugins/ExternalPf4jPluginManager.java

@@ -150,9 +150,12 @@ class ExternalPf4jPluginManager extends DefaultPluginManager
 			catch (PluginRuntimeException e)
 			{
 				if (!(e instanceof PluginAlreadyLoadedException))
+				{
+					if (!ExternalPluginManager.isDevelopmentMode())
 					{
 						String plugin = pluginPath.toString().substring(pluginsRoot.toString().length() + 1);
 						duplicatePlugins.add(plugin);
+					}
 					log.error("Could not load plugin {}", pluginPath, e);
 				}
 			}