Unify naming (a little)

lvmsnapshot.py

@@ -50,7 +50,7 @@ class Config:
         import toml
         if config_path is None:
             config_path = "config.toml"
-            global_config_path = "/etc/lvm-snapshot.toml"
+            global_config_path = "/etc/lvm-snapshots.toml"
             ENV_VAR = "LVM_SNAPSHOT_CONFIG"
             if not os.path.isfile(config_path) and os.path.isfile(global_config_path):
                 config_path = global_config_path