Catch UnknownSSHError and do not use return codes

The runners were still checking for the return codes of
create_ssh_master_connection instead of catching the exception.
We now catch the exceptions we calling the runners in main.

src/unisync/main.py

@@ -4,6 +4,7 @@
 from pathlib import Path
 
 from unisync.argparser import create_argparser
+from unisync.errors import UnknownSSHError, unisync_exit_fatal
 from unisync.runners import unisync_sync, unisync_add, unisync_mount
 from unisync.config import load_config
 from unisync.synchroniser import Synchroniser
@@ -38,7 +39,10 @@ def main():
 
     paths_manager = PathsManager(Path(config.roots.local), config.other.cache_dir_path)
 
+    try:
         cli_args.func(synchroniser, paths_manager, config)
+    except UnknownSSHError:
+        unisync_exit_fatal("Connection failed quitting")
 
 
 if __name__ == "__main__":

src/unisync/runners.py

@@ -5,11 +5,11 @@ from unisync.synchroniser import Synchroniser
 from unisync.paths import PathsManager
 from unisync.config import Config
 
+
 def unisync_sync(synchroniser:Synchroniser, paths_manager:PathsManager, config: Config):
     del config # The function signature must be the same for all runners
-    if synchroniser.create_ssh_master_connection() != 0:
-        print("Connection failed quitting")
-        return 1
+
+    synchroniser.create_ssh_master_connection()
     print("Connected to the remote.")
 
     synchroniser.sync_files(paths_manager.get_paths_to_sync())
@@ -24,9 +24,8 @@ def unisync_sync(synchroniser:Synchroniser, paths_manager:PathsManager, config:
 
 def unisync_add(synchroniser:Synchroniser, paths_manager:PathsManager, config: Config):
     del config # The function signature must be the same for all runners
-    if synchroniser.create_ssh_master_connection() != 0:
-        print("Connection failed quitting")
-        return 1
+
+    synchroniser.create_ssh_master_connection()
     print("Connected to the remote.")
 
     # TODO config or cli to skip this first sync