MINOR: h2: don't turn HTX header names to lower case anymore

Since HTX stores header names in lower case already, we don't need to
do it again anymore. This increased H2 performance by 2.7% on quick
tests, now making H2 overr HTX about 5.5% faster than H2 over H1.
diff --git a/src/mux_h2.c b/src/mux_h2.c
index dd321ec..2c8d1cc 100644
--- a/src/mux_h2.c
+++ b/src/mux_h2.c
@@ -3843,18 +3843,6 @@
 
 		list[hdr].n = htx_get_blk_name(htx, blk);
 		list[hdr].v = htx_get_blk_value(htx, blk);
-
-#if 1
-		{
-			/* FIXME: header names MUST be lower case in H2. For now it's
-			 * not granted by HTX so let's force them now.
-			 */
-			char *p;
-			for (p = list[hdr].n.ptr; p != list[hdr].n.ptr + list[hdr].n.len; p++)
-				if (unlikely(isupper(*p)))
-					*p = tolower(*p);
-		}
-#endif
 		hdr++;
 	}
 
@@ -4069,18 +4057,6 @@
 
 		list[hdr].n = htx_get_blk_name(htx, blk);
 		list[hdr].v = htx_get_blk_value(htx, blk);
-
-#if 1
-		{
-			/* FIXME: header names MUST be lower case in H2. For now it's
-			 * not granted by HTX so let's force them now.
-			 */
-			char *p;
-			for (p = list[hdr].n.ptr; p != list[hdr].n.ptr + list[hdr].n.len; p++)
-				if (unlikely(isupper(*p)))
-					*p = tolower(*p);
-		}
-#endif
 		hdr++;
 	}