[beeswax] Exception in watch/json in multi-statement query.

If executed multi-statement query has errors in second and further statements it raises an exception 
"local variable 'log' referenced before assignment" apps/beeswax/src/beeswax/views.py in watch_query_refresh_json, line 604 
Merge pull request #23 from petro-rudenko/patch-1

[beeswax] Exception in watch/json in multi-statement query.