A few more crashes fixed

app/src/main/java/eu/kanade/tachiyomi/ui/reader/ReaderActivity.kt

@@ -143,6 +143,8 @@ class ReaderActivity : BaseRxActivity<ReaderPresenter>() {
     }
 
     override fun onBackPressed() {
+        if (isFinishing) return
+
         presenter.onChapterLeft()
 
         val chapterToUpdate = presenter.getMangaSyncChapterToUpdate()
@@ -173,6 +175,7 @@ class ReaderActivity : BaseRxActivity<ReaderPresenter>() {
     }
 
     override fun dispatchKeyEvent(event: KeyEvent): Boolean {
+        if (!isFinishing) {
             val action = event.action
             val keyCode = event.keyCode
             when (keyCode) {
@@ -186,13 +189,14 @@ class ReaderActivity : BaseRxActivity<ReaderPresenter>() {
                         viewer?.moveToPrevious()
                     return true
                 }
-            else -> return super.dispatchKeyEvent(event)
             }
         }
+        return super.dispatchKeyEvent(event)
+    }
 
     fun onChapterError(error: Throwable) {
-        finish()
         Timber.e(error, error.message)
+        finish()
         toast(R.string.page_list_error)
     }