Mark t0027-auto-crlf as cheap enough for MinGW

t0027 is marked expensive, but really, for MinGW we want to run these
tests always.

Suggested by Thomas Braun.

Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>

t/t0027-auto-crlf.sh

@@ -4,9 +4,9 @@ test_description='CRLF conversion all combinations'
 
 . ./test-lib.sh
 
-if ! test_have_prereq EXPENSIVE
+if ! test_have_prereq EXPENSIVE && ! test_have_prereq MINGW
 then
-	skip_all="EXPENSIVE not set"
+	skip_all="Neither EXPENSIVE nor MINGW set"
 	test_done
 fi