pgAdmin 4 commit: Acquire a lock regardless of the authentication sourc

Acquire a lock regardless of the authentication sources while getting the database server connection.

Branch
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master

Details
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https://git.postgresql.org/gitweb?p=pgadmin4.git;a=commitdiff;h=a7ee4e5909cad3bbb26d6eca51a47f2847e772fa
Author: Khushboo Vashi <khushboo.vashi@enterprisedb.com>

Modified Files
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web/pgadmin/misc/bgprocess/processes.py         |  11 +-
web/pgadmin/utils/driver/psycopg2/connection.py | 164 +++++++++++-------------
web/pgadmin/utils/locker.py                     |  50 ++++++++
3 files changed, 131 insertions(+), 94 deletions(-)