git-request-pull.sh: remove -e switch to shell interpreter which breaks ksh

The -e option causes the shell to exit immediately when a command exits with a non-zero exit status. This does not seem to cause a problem for Bash, but it does cause a problem for the Korn shell, like Solaris's xpg4/sh, whose unset utility returns non-zero if it is passed a variable name which was not previously set. When using xpg4/sh, git-request-pull exits while sourcing git-sh-setup since git-sh-setup tries to unset the CDPATH environment variable. When git-request-pull was originally written, it did not do any error checking and it used this shell feature to exit when an error occurred. This script now performs proper error checking and provides useful error messages, so this -e option appears to be merely a historical artifact and can be removed. Kudos to Jonathan Nieder for introducing t5150 which exercises the request-pull code path. Suggested-by: Brandon Casey <drafnel@gmail.com> Signed-off-by: Jonathan Nieder <jrnieder@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>