DOC: this is development again
This is basically a revert of commit eb1a3ee5 ("DOC: mention in INSTALL
haproxy 2.1 is a stable stable version").
diff --git a/INSTALL b/INSTALL
index 78395ac..40e3a04 100644
--- a/INSTALL
+++ b/INSTALL
@@ -1,15 +1,15 @@
Installation instructions for HAProxy
=====================================
-HAProxy 2.1 is a stable version, which means that it will get fixes for bugs as
-they are discovered till around Q1 2021 and should not receive new features.
-This version is mostly suited at experienced users who are willing to quickly
-follow updates. New users are encouraged to use long term supported versions
-such as the ones provided by their software vendor or Linux distribution, as
-such versions require far less common updates. If for any reason you'd prefer
-a different version than the one packaged for your system, you want to be
-certain to have all the fixes or to get some commercial support, other choices
-are available at http://www.haproxy.com/.
+This is a development version, so it is expected to break from time to time,
+to add and remove features without prior notification and it should not be used
+in production. If you are not used to build from sources or if you are not used
+to follow updates then it is recommended that instead you use the packages
+provided by your software vendor or Linux distribution. Most of them are taking
+this task seriously and are doing a good job at backporting important fixes. If
+for any reason you'd prefer to use a different version than the one packaged
+for your system, you want to be certain to have all the fixes or to get some
+commercial support, other choices are available at http://www.haproxy.com/.
Areas covered in this document