Move mime-parameter folding to top of loop.

The mime parameter folder doesn't make use of the encoding check
done be the code that is now below it, it does its own.  So it
makes more sense to take that branch first.  This will simplify
subsequent changes.

Author: bitdancer

Lib/email/_header_value_parser.py

@@ -2858,6 +2858,11 @@ def _refold_parse_tree(parse_tree, *, policy):
         if part is end_ew_not_allowed:
             wrap_as_ew_blocked -= 1
             continue
+        if part.token_type == 'mime-parameters':
+            # Mime parameter folding (using RFC2231) is extra special.
+            _fold_mime_parameters(part, lines, maxlen, encoding)
+            last_word_is_ew = False
+            continue
         tstr = str(part)
         if not want_encoding:
             if part.token_type in ('ptext', 'vtext'):
@@ -2879,12 +2884,6 @@ def _refold_parse_tree(parse_tree, *, policy):
                 charset = 'utf-8'
             want_encoding = True
 
-        if part.token_type == 'mime-parameters':
-            # Mime parameter folding (using RFC2231) is extra special.
-            _fold_mime_parameters(part, lines, maxlen, encoding)
-            last_word_is_ew = False
-            continue
-
         if want_encoding and not wrap_as_ew_blocked:
             if not part.as_ew_allowed:
                 want_encoding = False