Fix RemovedIn20Warning: retrieving row members using strings

"RemovedIn20Warning: Retrieving row members using strings or other non-integers is deprecated"

lib/galaxy/jobs/handler.py

@@ -879,7 +879,7 @@ def get_user_job_count_per_destination(self, user_id):
                 )
                 .group_by(model.Job.table.c.destination_id)
             )
-            for row in result:
+            for row in result.mapping():
                 # Add the count from the database to the cached count
                 rval[row["destination_id"]] = rval.get(row["destination_id"], 0) + row["job_count"]
         return rval
@@ -897,7 +897,7 @@ def __cache_user_job_count_per_destination(self):
                 .where(and_(model.Job.table.c.state.in_((model.Job.states.QUEUED, model.Job.states.RUNNING))))
                 .group_by(model.Job.table.c.user_id, model.Job.table.c.destination_id)
             )
-            for row in result:
+            for row in result.mappings():
                 if row["user_id"] not in self.user_job_count_per_destination:
                     self.user_job_count_per_destination[row["user_id"]] = {}
                 self.user_job_count_per_destination[row["user_id"]][row["destination_id"]] = row["job_count"]