pgAdmin 4 commit: Fixed TypeError 'NoneType' object is not sub scriptab

Fixed TypeError 'NoneType' object is not sub scriptable. Fixes #6580

Branch
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master

Details
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https://git.postgresql.org/gitweb?p=pgadmin4.git;a=commitdiff;h=9e8af67202d3e0da78e6da5210f04bcd7ec03373
Author: Rahul Shirsat 

Modified Files
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docs/en_US/release_notes.rst     |  1 +
docs/en_US/release_notes_5_6.rst | 20 ++++++++++++++++++++
web/pgadmin/__init__.py          |  6 +++---
3 files changed, 24 insertions(+), 3 deletions(-)