Creating the external gzip process fails, because we

call execve() with "gzip" without full path.
Let's look for it in the PATH instead and drop the
passing of the environment. There seems to be no
reason why gzip should need the httpd environment.


git-svn-id: https://svn.apache.org/repos/asf/httpd/httpd/trunk@756675 13f79535-47bb-0310-9956-ffa450edef68