Simplify set_logging() indexing (ultralytics#6042)

utils/general.py

@@ -46,7 +46,7 @@
 
 def set_logging(name=None, verbose=True):
     # Sets level and returns logger
-    for h in logging.root.handlers[:]:
+    for h in logging.root.handlers:
         logging.root.removeHandler(h)  # remove all handlers associated with the root logger object
     rank = int(os.getenv('RANK', -1))  # rank in world for Multi-GPU trainings
     logging.basicConfig(format="%(message)s", level=logging.INFO if (verbose and rank in (-1, 0)) else logging.WARNING)