pgAdmin 4 commit: Update scan and index scan EXPLAIN icons forgreater

Update scan and index scan EXPLAIN icons for greater clarity. Fixes #3021

Branch
------
master

Details
-------
https://git.postgresql.org/gitweb?p=pgadmin4.git;a=commitdiff;h=5cea5f84855a1b308769a537e9f5bbc332833566
Author: Chethana Kumar 

Modified Files
--------------
web/pgadmin/misc/static/explain/img/ex_index_scan.svg | 2 +-
web/pgadmin/misc/static/explain/img/ex_scan.svg       | 2 +-
2 files changed, 2 insertions(+), 2 deletions(-)