[api] Do not reset Package.commit_opts

If we reset commit_opts it'll happen sometimes in the middle
of the callbacks which is not what we want. Fixes #1428

src/api/app/models/package.rb

@@ -729,7 +729,6 @@ def write_to_backend
         logger.tagged('backend_sync') { logger.warn "Not saving Package #{self.project.name}/#{self.name}, global_write_through is off" }
       end
     end
-    @commit_opts = {}
     true
   end
 
@@ -759,7 +758,6 @@ def delete_on_backend
         logger.tagged('backend_sync') { logger.warn "Not deleting Package #{self.project.name}/#{self.name}, global_write_through is off" }
       end
     end
-    @commit_opts = {}
     true
   end