Fixed bug where default formatter was set incorrectly

When string formatter was created, the default formatter was also set.
This might affect code where a formatter is created but never set.

SetFormatter should be used for all cases and code depending on this
missbehavior need to be fixed.

Author: op

format.go

@@ -241,8 +241,6 @@ func NewStringFormatter(format string) (*stringFormatter, error) {
 		return nil, err
 	}
 
-	formatter.def = fmter
-
 	return fmter, nil
 }