task#1847 - smail fixes:

- getRevision writes git output to log (requires enabled debugging to see it)
- added check for tmpdir

public_html/deployment/classes/vcs.git.class.php

@@ -261,8 +261,6 @@ class vcs implements iVcs {
                 }
                 $this->_aRemoteBranches = $aReturn;
                 $oCache->write($aReturn, $iTtl);
-            } else {
-            $this->log(__FUNCTION__." FAILD with rc=$iRc $sGitCmd", 'error');
             }
         } else {
             $this->_aRemoteBranches = $oCache->read();