Fix doc build from tarball using eventlet>0.19.0

When subprocess is monkey-patched using eventlet, trying to catch
subprocess.CalledProcessError exception won't work [1]. This breaks
doc build from a tarball, so let's catch all exceptions.

[1] https://github.com/eventlet/eventlet/issues/357

Change-Id: Ibcf535c6e4994a67fc3ec71631a81ecb91dd2845
Closes-Bug: #1693148

oslosphinx/__init__.py

@@ -28,7 +28,7 @@ def _guess_cgit_link():
         git_remote = subprocess.check_output(
             ['git', 'config', '--local', '--get', 'remote.origin.url']
         )
-    except (OSError, subprocess.CalledProcessError):
+    except Exception:
         # git is not present or the command failed
         return None
     else: