patch 8.1.0810: too many #ifdefs

Problem:    Too many #ifdefs.
Solution:   Graduate FEAT_MBYTE, part 4.
diff --git a/src/version.c b/src/version.c
index 79778cd..7898c1a 100644
--- a/src/version.c
+++ b/src/version.c
@@ -459,11 +459,7 @@
 	"+multi_byte_ime",
 # endif
 #else
-# ifdef FEAT_MBYTE
 	"+multi_byte",
-# else
-	"-multi_byte",
-# endif
 #endif
 #ifdef FEAT_MULTI_LANG
 	"+multi_lang",
@@ -792,6 +788,8 @@
 static int included_patches[] =
 {   /* Add new patch number below this line */
 /**/
+    810,
+/**/
     809,
 /**/
     808,
@@ -3052,14 +3050,12 @@
 	for (l = 0; p[l] != NUL
 			 && (l == 0 || (p[l] != '<' && p[l - 1] != '>')); ++l)
 	{
-#ifdef FEAT_MBYTE
 	    if (has_mbyte)
 	    {
 		clen += ptr2cells(p + l);
 		l += (*mb_ptr2len)(p + l) - 1;
 	    }
 	    else
-#endif
 		clen += byte2cells(p[l]);
 	}
 	screen_puts_len(p, l, row, col, *p == '<' ? HL_ATTR(HLF_8) : attr);