Do not strip CR when grepping HTTP headers.

By default, MSYS grep reads in text-mode and converts CRLF into LF line
endings. For testing HTTP use binary mode (-U) as checking is done for
CR in HTTP headers
Signed-off-by: NEric Sunshine <sunshine@sunshineco.com>
Signed-off-by: NPat Thoyts <patthoyts@users.sourceforge.net>

t/t5560-http-backend-noserver.sh

@@ -5,6 +5,8 @@ test_description='test git-http-backend-noserver'
 
 HTTPD_DOCUMENT_ROOT_PATH="$TRASH_DIRECTORY"
 
+test_have_prereq MINGW && export GREP_OPTIONS=-U
+
 run_backend() {
 	echo "$2" |
 	QUERY_STRING="${1#*\?}" \

t/test-lib.sh

@@ -970,6 +970,7 @@ case $(uname -s) in
 	# no POSIX permissions
 	# backslashes in pathspec are converted to '/'
 	# exec does not inherit the PID
+	test_set_prereq MINGW
 	;;
 *)
 	test_set_prereq POSIXPERM