MINOR: version: mention that it's an LTS release now

The new version is going to be LTS up to around Q2 2025.
diff --git a/include/haproxy/version.h b/include/haproxy/version.h
index 446ce5a..6c06807 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: development branch - not safe for use in production."
+#define PRODUCT_STATUS   "Status: long-term supported branch - will stop receiving fixes around Q2 2025."
 #endif
 
 #ifdef CONFIG_PRODUCT_URL_BUGS