pgAdmin 4 commit: Updated jQuery version as they have fixed some vulner

Updated jQuery version as they have fixed some vulnerability issue.

Branch
------
master

Details
-------
https://git.postgresql.org/gitweb?p=pgadmin4.git;a=commitdiff;h=20c42d878bbd291ffacf3e961bb2e5675f20b601

Modified Files
--------------
web/package.json |   2 +-
web/yarn.lock    | 509 +------------------------------------------------------
2 files changed, 6 insertions(+), 505 deletions(-)