Git command not found with FastCGI

Hi

I've the following setup and could not get git tags to show up:

- CentOS Linux release 7.3.1611
- php70u-fpm.x86_64 7.0.15-1.ius.centos7
- nginx.x86_64 1:1.10.2-1.el7

I started debugging this and figured out that command_exists('git') gives an empty return.

If I run this locally I get '/usr/bin/git', if I run an interactive shell as nginx (sudo -u nginx php -a) I get '/bin/git'. I am unsure what the best patch to fix that would be.

If I hardcode '/usr/bin/git', environment_indicator_execute_os_command() has no problem executing git describe.