MINOR: version: it's development again.

This reverts commit 0badabc381bc9c0d6be7479d528a5d549d6185f4.
diff --git a/include/haproxy/version.h b/include/haproxy/version.h
index 4ec2267..f2bf12a 100644
--- a/include/haproxy/version.h
+++ b/include/haproxy/version.h
@@ -39,7 +39,7 @@
 #ifdef  CONFIG_PRODUCT_STATUS
 #define PRODUCT_STATUS    CONFIG_PRODUCT_STATUS
 #else
-#define PRODUCT_STATUS   "Status: stable branch - will stop receiving fixes around Q1 2022."
+#define PRODUCT_STATUS   "Status: development branch - not safe for use in production."
 #endif
 
 #ifdef CONFIG_PRODUCT_URL_BUGS