remove invalid assertion
remove invalid assertion

replace_reply_cb() can be called when we don't have a vCard set request in
progress, so it's wrong to assert that priv->edit_pipeline_item is not NULL.
Specifically, it's called when a pre-set get request fails.

mlundblad/telepathy-gabble,Ziemin/telepathy-gabble,Ziemin/telepathy-gabble,community-ssu/telepathy-gabble,jku/telepathy-gabble,mlundblad/telepathy-gabble,community-ssu/telepathy-gabble,jku/telepathy-gabble,mlundblad/telepathy-gabble,community-ssu/telepathy-gabble,community-ssu/telepathy-gabble,jku/telepathy-gabble,Ziemin/telepathy-gabble,Ziemin/telepathy-gabble