Revert "Revert "Merge branch 'master' of https://github.com/discourse/discourse""

This reverts commit 20780a1eeed56b321daf18ee6bbfe681a51d1bf4.

* SECURITY: re-adds accidentally reverted commit:
  03d26cd6: ensure embed_url contains valid http(s) uri
* when the merge commit e62a85cf was reverted, git chose the 2660c2e2 parent to land on
  instead of the 03d26cd6 parent (which contains security fixes)

lib/backup_restore/backup_file_handler.rb

@@ -65,9 +65,10 @@ module BackupRestore
       return if !@is_archive
 
       log "Unzipping archive, this may take a while..."
-      pipeline = Compression::Pipeline.new([Compression::Tar.new, Compression::Gzip.new])
-      unzipped_path = pipeline.decompress(@tmp_directory, @archive_path, available_size)
-      pipeline.strip_directory(unzipped_path, @tmp_directory)
+      Discourse::Utils.execute_command(
+        'tar', '--extract', '--gzip', '--file', @archive_path, '--directory', @tmp_directory,
+        failure_message: "Failed to decompress archive."
+      )
     end
 
     def extract_db_dump