modules: readme files regenerated - modules ... [skip ci]

src/modules/db_cassandra/README

@@ -61,6 +61,13 @@ Chapter 1. Admin Guide
 
 1. Overview
 
+   Note: the module requires old version of external library, not
+   compiling with those available out of the stock in the Linux
+   distributions. It is going to be kept for a while in case someone wants
+   to pick it up and upgrade. Also, the module was never extensively
+   tested, therefore take the appropriate actions in case you plan to use
+   it.
+
    Db_cassandra is one of the Kamailio database modules. It does not
    export any functions executable from the configuration scripts, but it
    exports a subset of functions using the database API, and thus, other