tests: Clean out unnecessary ifs from GitHubAuthBackendTest helper.
tests: Clean out unnecessary ifs from GitHubAuthBackendTest helper.

After the refactor moving this logic into a helper inside of
GitHubAuthBackendTest, these checks became unnecessary and always True.

shubhamdhama/zulip,andersk/zulip,eeshangarg/zulip,kou/zulip,shubhamdhama/zulip,kou/zulip,punchagan/zulip,showell/zulip,shubhamdhama/zulip,timabbott/zulip,zulip/zulip,zulip/zulip,showell/zulip,hackerkid/zulip,showell/zulip,synicalsyntax/zulip,punchagan/zulip,rht/zulip,shubhamdhama/zulip,punchagan/zulip,shubhamdhama/zulip,hackerkid/zulip,brainwane/zulip,zulip/zulip,eeshangarg/zulip,eeshangarg/zulip,kou/zulip,synicalsyntax/zulip,andersk/zulip,punchagan/zulip,timabbott/zulip,rht/zulip,brainwane/zulip,showell/zulip,andersk/zulip,zulip/zulip,hackerkid/zulip,zulip/zulip,andersk/zulip,punchagan/zulip,kou/zulip,shubhamdhama/zulip,synicalsyntax/zulip,zulip/zulip,rht/zulip,rht/zulip,zulip/zulip,synicalsyntax/zulip,hackerkid/zulip,timabbott/zulip,andersk/zulip,rht/zulip,eeshangarg/zulip,andersk/zulip,brainwane/zulip,timabbott/zulip,eeshangarg/zulip,kou/zulip,rht/zulip,brainwane/zulip,andersk/zulip,brainwane/zulip,timabbott/zulip,showell/zulip,synicalsyntax/zulip,showell/zulip,synicalsyntax/zulip,hackerkid/zulip,kou/zulip,timabbott/zulip,shubhamdhama/zulip,punchagan/zulip,brainwane/zulip,punchagan/zulip,brainwane/zulip,synicalsyntax/zulip,eeshangarg/zulip,hackerkid/zulip,timabbott/zulip,hackerkid/zulip,rht/zulip,showell/zulip,kou/zulip,eeshangarg/zulip