email_mirror: Add test to cover empty body after footer stripping.
email_mirror: Add test to cover empty body after footer stripping.

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