SubmittingPatches: clarify MUA discussion with "the"

Without the word "the", the sentence is a little harder to read. The
word "the" makes it clearer that the comment refers to discrete patches,
and not portions of individual patches.

Signed-off-by: Daniel Watson <ozzloy@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

Documentation/SubmittingPatches

@@ -543,7 +543,7 @@ trigger a new CI build to ensure all tests pass.
 [[mua]]
 == MUA specific hints
 
-Some of patches I receive or pick up from the list share common
+Some of the patches I receive or pick up from the list share common
 patterns of breakage.  Please make sure your MUA is set up
 properly not to corrupt whitespaces.