fix(client): Hide the border around the marketing snippet for the firstrun flow.
fix(client): Hide the border around the marketing snippet for the firstrun flow.

fixes #2709

TDA/fxa-content-server,ofer43211/fxa-content-server,shane-tomlinson/fxa-content-server,TDA/fxa-content-server,ReachingOut/fxa-content-server,atiqueahmedziad/fxa-content-server,vladikoff/fxa-content-server,vladikoff/fxa-content-server,npestana/fxa-content-server,TDA/fxa-two-factor-auth,mozilla/fxa-content-server,TDA/fxa-two-factor-auth,npestana/fxa-content-server,ReachingOut/fxa-content-server,shane-tomlinson/fxa-content-server,swatilk/fxa-content-server,mozilla/fxa-content-server,atiqueahmedziad/fxa-content-server,swatilk/fxa-content-server,swatilk/fxa-content-server,shane-tomlinson/fxa-content-server,atiqueahmedziad/fxa-content-server,mozilla/fxa-content-server,TDA/fxa-content-server,ReachingOut/fxa-content-server,vladikoff/fxa-content-server,ofer43211/fxa-content-server,TDA/fxa-two-factor-auth,ofer43211/fxa-content-server,npestana/fxa-content-server