Remove use of rescue nil.

* `rescue nil` is a really bad pattern to use in our code base.
  We should rescue errors that we expect the code to throw and
  not rescue everything because we're unsure of what errors the
  code would throw. This would reduce the amount of pain we face
  when debugging why something isn't working as expexted. I've
  been bitten countless of times by errors being swallowed as a
  result during debugging sessions.

app/services/handle_chunk_upload.rb

@@ -42,8 +42,8 @@ class HandleChunkUpload
     tmp_directory   = @params[:tmp_directory]
 
     # delete destination files
-    File.delete(upload_path) rescue nil
-    File.delete(tmp_upload_path) rescue nil
+    File.delete(upload_path)
+    File.delete(tmp_upload_path)
 
     # merge all the chunks
     File.open(tmp_upload_path, "a") do |file|
@@ -59,7 +59,7 @@ class HandleChunkUpload
     FileUtils.mv(tmp_upload_path, upload_path, force: true)
 
     # remove tmp directory
-    FileUtils.rm_rf(tmp_directory) rescue nil
+    FileUtils.rm_rf(tmp_directory)
   end
 
 end

app/services/post_alerter.rb

@@ -405,8 +405,7 @@ class PostAlerter
     )
 
     if created.id && !existing_notification && NOTIFIABLE_TYPES.include?(type) && !user.suspended?
-      # we may have an invalid post somehow, dont blow up
-      post_url = original_post.url rescue nil
+      post_url = original_post.url
       if post_url
         payload = {
          notification_type: type,