Allow IBB FT to bare JIDs again

Currently works on released gajim, but not on nightly.

This explicit check for resource in the to-jid just returns if there is no
resource. It doesn't even cancel the file transfer or anything, it just
stops... which looks to the user like a file transfer hang.  Removing
the check makes Gajim work as expected.

Closes #8581

src/common/protocol/bytestream.py

@@ -843,8 +843,6 @@ class ConnectionIBBytestream(ConnectionBytestream):
         Take into account that recommended stanza size is 4k and IBB uses
         base64 encoding that increases size of data by 1/3.
         """
-        if not nbxmpp.JID(to).getResource():
-            return
         file_props = FilesProp.getFilePropBySid(sid)
         file_props.direction = '|>' + to
         file_props.block_size = blocksize