DOC: install: recommend pcre2

Makefile comments are also updated to recommend the PCRE2 related
options. PCRE1 is EOL by now:

   https://www.mail-archive.com/haproxy@formilux.org/msg41326.html

(cherry picked from commit 2192dfa6b69f499443afd0f4ffb74eea550d0ecb)
Signed-off-by: Christopher Faulet <cfaulet@haproxy.com>
(cherry picked from commit 5916f14d063cfa8fb2f910fb13b8aa069efc5c84)
[wt: trivial ctx adj]
Signed-off-by: Willy Tarreau <w@1wt.eu>
diff --git a/Makefile b/Makefile
index cba3fbe..014d4e5 100644
--- a/Makefile
+++ b/Makefile
@@ -23,8 +23,8 @@
 #   USE_PCRE2_JIT        : enable JIT for faster regex on libpcre2
 #   USE_POLL             : enable poll(). Automatic.
 #   USE_THREAD           : enable threads support.
-#   USE_STATIC_PCRE      : enable static libpcre. Recommended.
-#   USE_STATIC_PCRE2     : enable static libpcre2.
+#   USE_STATIC_PCRE      : enable static libpcre.
+#   USE_STATIC_PCRE2     : enable static libpcre2. Recommended.
 #   USE_TPROXY           : enable transparent proxy. Automatic.
 #   USE_LINUX_TPROXY     : enable full transparent proxy. Automatic.
 #   USE_LINUX_SPLICE     : enable kernel 2.6 splicing. Automatic.