Revert unneccessary changes made in bpo-30296 and apply other improvements. (GH-2624)

diff --git a/Lib/logging/config.py b/Lib/logging/config.py
index 7927e76..1b0faca 100644
--- a/Lib/logging/config.py
+++ b/Lib/logging/config.py
@@ -460,7 +460,7 @@
             c = self.resolve(c)
         props = config.pop('.', None)
         # Check for valid identifiers
-        kwargs = dict((k, config[k]) for k in config if valid_ident(k))
+        kwargs = {k: config[k] for k in config if valid_ident(k)}
         result = c(**kwargs)
         if props:
             for name, value in props.items():
@@ -723,7 +723,7 @@
                 config['address'] = self.as_tuple(config['address'])
             factory = klass
         props = config.pop('.', None)
-        kwargs = dict((k, config[k]) for k in config if valid_ident(k))
+        kwargs = {k: config[k] for k in config if valid_ident(k)}
         try:
             result = factory(**kwargs)
         except TypeError as te: