Elasticsearch query runner: mappings_data is not defined

[idlefella]

Issue Summary

When executing an elasticsearch query, a message appears that "mappings_data is not defined".

Steps to Reproduce

1. Clone the latest version (master branch) from github and install the dev environment.
2. Add an elasticsearch instance and try to execute a query, e.g.
   {"query": {'"match_all": {}}
3. A message appears that the query was not successfull (mappings_data is not defined)

The bug is quite obvious since

redash/redash/query_runner/elasticsearch.py

Line 126 in 3bc98fb

for index_name in mappings_data:

refers to mappings_data, which is nowhere defined in the same file. Unfortunately I didn't find out what this mappings_data should contain.

Technical details:

• Redash Version: master branch
• Browser/OS: Linux/Chrome

[arikfr]

Fixed. Thanks!