config: Fold ConfigStatic into Config

Now that we no longer have two different configuration variants, we can
remove the abstract class and make Config the primary interface.

Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>

kas/build.py

@@ -24,7 +24,7 @@
 """
 
 import os
-from .config import load_config
+from .config import Config
 from .libkas import find_program, run_cmd, kasplugin
 from .libcmds import (Macro, Command, SetupDir, SetupProxy,
                       CleanupSSHAgent, SetupSSHAgent, SetupEnviron,
@@ -71,7 +71,7 @@ class Build:
         if args.cmd != 'build':
             return False
 
-        cfg = load_config(args.config, args.target, args.task)
+        cfg = Config(args.config, args.target, args.task)
 
         macro = Macro()