VoIP calls: Fixup whitespace.

Set modelines and reindent to match the files in the top-level ui
directory.

Change-Id: I7ea221e76a4b0ad3b6bcf7a3c8b4645c16aecbba
Reviewed-on: https://code.wireshark.org/review/5325
Reviewed-by: Gerald Combs <gerald@wireshark.org>