fixed regex matching of stderr

setup.py

@@ -6,7 +6,7 @@ try:
 except ImportError:
     from distutils import setup
 
-version = '0.3.3'
+version = '0.3.4'
 
 setup(
         name='zsnapper',

zsnaplib/__init__.py

@@ -37,7 +37,7 @@ def do_zfs_command(args, zfs_cmd, pipecmd=None):
     # check if we try to create a snapshot that already exists. This can happen
     # if the script is run every minute and it takes more time than that to
     # create all snapshots
-    if ctrl_proc.returncode == 1 and re_match(re_err_ok, err):
+    if ctrl_proc.returncode == 1 and re.match(re_err_ok, err):
         pass
     elif ctrl_proc.returncode != 0:
         raise ZFSSnapshotError('Failed to execute {}: {}'.format(cmd, err))