Catch errors in case git is not installed

Signed-off-by: Michal Čihař <michal@cihar.com>

weblate/__init__.py

@@ -70,7 +70,7 @@ if RUNNING_GIT:
         # Mark version as devel if it is
         if not GIT_RELEASE:
             VERSION += '-dev'
-    except RepositoryException:
+    except (RepositoryException, OSError):
         # Import failed or git has troubles reading
         # repo (eg. swallow clone)
         RUNNING_GIT = False

weblate/requirements.py

@@ -131,12 +131,15 @@ def get_versions():
         '2.5',
     ))
 
-    result.append((
-        'Git',
-        'http://git-scm.com/',
-        GitRepository.get_version(),
-        '1.6',
-    ))
+    try:
+        result.append((
+            'Git',
+            'http://git-scm.com/',
+            GitRepository.get_version(),
+            '1.6',
+        ))
+    except OSError:
+        raise Exception('Failed to run git, please install it.')
 
     name = 'South'
     url = 'http://south.aeracode.org/'