t-ctype: align output of i

The unit test reports misclassified characters like this:

   # check "isdigit(i) == !!memchr("123456789", i, len)" failed at t/unit-tests/t-ctype.c:36
   #    left: 1
   #   right: 0
   #        i: 0x30

Reduce the indent of i to put its colon directly below the ones in the
preceding lines for consistency.

Signed-off-by: René Scharfe <[email protected]>
Signed-off-by: Junio C Hamano <[email protected]>

Author: rscharfe

t/unit-tests/t-ctype.c

@@ -8,7 +8,7 @@ static void test_ctype_##func(void) { \
 		BUILD_ASSERT_OR_ZERO(sizeof(string[0]) == sizeof(char)); \
 	for (int i = 0; i < 256; i++) { \
 		if (!check_int(func(i), ==, !!memchr(string, i, len))) \
-			test_msg("       i: 0x%02x", i); \
+			test_msg("      i: 0x%02x", i); \
 	} \
 	check(!func(EOF)); \
 }