- avoid crash by fixing "first" and "last" pointers of of the ts_entry_t after ts_urecord_t deletion

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#### Description <!-- Describe your changes in detail -->

tsilo module didn't reset "**first**" and "**last**" pointers of a doubly linked list of **ts_urecord_t** objects. It worked correctly only when there were no hash collisions and each ts_entry slot had only one **ts_urecord_t** object. To faster reproduce the problem one can set **modparam("tsilo", "hash_size", 2)** and run a light load test (5...10 simultaneous call setups). You can view, comment on, or merge this pull request online at:

https://github.com/kamailio/kamailio/pull/1302

-- Commit Summary --

* tsilo: fix internal data structures

-- File Changes --

M src/modules/tsilo/ts_hash.c (8)

-- Patch Links --

https://github.com/kamailio/kamailio/pull/1302.patch https://github.com/kamailio/kamailio/pull/1302.diff