remove invalid fstr setting (#3682)

examples/pylintrc

@@ -187,7 +187,7 @@ never-returning-functions=sys.exit
 [LOGGING]
 
 # Format style used to check logging format string. `old` means using %
-# formatting, `new` is for `{}` formatting,and `fstr` is for f-strings.
+# formatting and `new` is for `{}` formatting.
 logging-format-style=old
 
 # Logging modules to check that the string format arguments are in logging