Fix crash on plugin reload

[CranberrySoup]

The patch fixes this error:

Process: com.lagradost.cloudstream3.prerelease.debug, PID: 13521
java.util.ConcurrentModificationException
at java.util.LinkedHashMap$LinkedHashIterator.nextNode(LinkedHashMap.java:760)
at java.util.LinkedHashMap$LinkedKeyIterator.next(LinkedHashMap.java:782)
at com.lagradost.cloudstream3.utils.Event.invoke(Event.kt:25)
at com.lagradost.cloudstream3.plugins.PluginManager.loadAllLocalPlugins(PluginManager.kt:452)
at com.lagradost.cloudstream3.plugins.PluginManager.hotReloadAllLocalPlugins(PluginManager.kt:423)
at com.lagradost.cloudstream3.MainActivity$Companion.handleAppIntentUrl(MainActivity.kt:377)
at com.lagradost.cloudstream3.MainActivity.handleAppIntent(MainActivity.kt:696)
at com.lagradost.cloudstream3.MainActivity.onNewIntent(MainActivity.kt:688)
at android.app.Activity.performNewIntent(Activity.java:8321)
at android.app.Instrumentation.callActivityOnNewIntent(Instrumentation.java:1517)
at android.app.Instrumentation.callActivityOnNewIntent(Instrumentation.java:1530)
at android.app.ActivityThread.deliverNewIntents(ActivityThread.java:3822)
at android.app.ActivityThread.handleNewIntent(ActivityThread.java:3829)
at android.app.servertransaction.NewIntentItem.execute(NewIntentItem.java:56)
at android.app.servertransaction.ActivityTransactionItem.execute(ActivityTransactionItem.java:45)
at android.app.servertransaction.TransactionExecutor.executeCallbacks(TransactionExecutor.java:135)
at android.app.servertransaction.TransactionExecutor.execute(TransactionExecutor.java:95)
at android.app.ActivityThread$H.handleMessage(ActivityThread.java:2307)
at android.os.Handler.dispatchMessage(Handler.java:106)
at android.os.Looper.loopOnce(Looper.java:201)
at android.os.Looper.loop(Looper.java:288)
at android.app.ActivityThread.main(ActivityThread.java:7872)
at java.lang.reflect.Method.invoke(Native Method)
at com.android.internal.os.RuntimeInit$MethodAndArgsCaller.run(RuntimeInit.java:548)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:936)

Caused by modifying observers when iterating over them. This happens often when using deployWithAdb, which reloads all plugins.