Add 0.9.10 changelog entry.

ChangeLog

@@ -1,3 +1,12 @@
+0.9.10:
+	* Do not dereference null pointer on learning.
+	* Fix some extreme cases in BAYES.
+	* Add a workaround to avoid bad HTML messages breaking.
+	* Build with -O2 flags by default.
+	* Add constraints to limit DNS requests count per task.
+	* Add workaround for SURBL DNS flood.
+	* Set error if rspamd cannot learn anything.
+
 0.9.9:
 	* Don't use RWL_SPAMHAUS_WL (unknown result) for whitelisting (by @fatalbanana)
 	* Import updated public suffix list (by @fatalbanana)