[RELEASE] Released version 1.5-dev6

Released version 1.5-dev6 with the following main changes :
    - [BUG] stream_sock: use get_addr_len() instead of sizeof() on sockaddr_storage
    - [BUG] TCP source tracking was broken with IPv6 changes
    - [BUG] stick-tables did not work when converting IPv6 to IPv4
    - [CRITICAL] fix risk of crash when dealing with space in response cookies
diff --git a/VERSION b/VERSION
index 6587f9f..465bd7c 100644
--- a/VERSION
+++ b/VERSION
@@ -1 +1 @@
-1.5-dev5
+1.5-dev6