gitweb: use start_form, not startform that was removed in CGI.pm 4.04
gitweb: use start_form, not startform that was removed in CGI.pm 4.04

CGI.pm 4.04 removed the startform method, which had previously been
deprecated in favour of start_form.  Changes file for CGI.pm says:

    4.04 2014-09-04
     [ REMOVED / DEPRECATIONS ]
	- startform and endform methods removed (previously deprecated,
	  you should be using the start_form and end_form methods)

Signed-off-by: Roland Mas <ce654778164692adb76e9cc1c6bccbf92d7326fd@debian.org>
Reviewed-by: Jakub Narębski <a6a1517a087f9f64a72f41a0de57ff01fbb0e412@gmail.com>
Signed-off-by: Junio C Hamano <a6723cc3f76163bf7adb636a73ac3b0ceb3e6b9b@pobox.com>

destenson/git,destenson/git,destenson/git,destenson/git,destenson/git,destenson/git,destenson/git,destenson/git