streamclone: move "streaming all changes" message location

Previously, the message was printed after we requested and started
processing the remote stream. This seems like something that we should
do before calling out to the remote. Moving it also makes it easier to
deal with the bundle2 implementation.

mercurial/streamclone.py

@@ -113,6 +113,8 b' def maybeperformlegacystreamclone(pullop'
     if remote.capable('branchmap'):
         rbranchmap = remote.branchmap()
 
+    repo.ui.status(_('streaming all changes\n'))
+
     fp = remote.stream_out()
     l = fp.readline()
     try:
@@ -245,7 +247,6 b' def consumev1(repo, fp, filecount, bytec'
     """
     lock = repo.lock()
     try:
-        repo.ui.status(_('streaming all changes\n'))
         repo.ui.status(_('%d files to transfer, %s of data\n') %
                        (filecount, util.bytecount(bytecount)))
         handled_bytes = 0