Small fix to prevent an exception from being thrown on bad input.
Small fix to prevent an exception from being thrown on bad input.

* tools/hook-scripts/mailer/mailer.py:
  - wrap a conversion to an integer with a try/except. if the argument is
    not an integer, then they goofed -- display the usage.


git-svn-id: f8a4e5e023278da1e04e203c7fe051e3c4285d88@853065 13f79535-47bb-0310-9956-ffa450edef68

YueLinHo/Subversion,wbond/subversion,YueLinHo/Subversion,YueLinHo/Subversion,wbond/subversion,wbond/subversion,wbond/subversion,wbond/subversion,YueLinHo/Subversion,YueLinHo/Subversion,YueLinHo/Subversion,YueLinHo/Subversion,wbond/subversion,YueLinHo/Subversion,wbond/subversion