Remove unnecessary error message in app_dial.c

Remove unnecessary error message in app_dial.c

The error message for failure to stop autoservice after a gosub or macro call
during a dial was removed for macro while Asterisk 1.4 was still being actively
developed. The corresponding gosub error message was never removed.

(closes issue ASTERISK-19551)
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Merged revisions 361329 from http://svn.asterisk.org/svn/asterisk/branches/1.8
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Merged revisions 361330 from http://svn.asterisk.org/svn/asterisk/branches/10

git-svn-id: https://origsvn.digium.com/svn/asterisk/trunk@361331 65c4cc65-6c06-0410-ace0-fbb531ad65f3