Former member back in the WoT with only 4 certifiers

Former member GerardSiegle (5tp5GZRGfDPm3uBaadWLpJ7x6C1ZP5PkyiZoW3oe7ukH) was added back on block 284605 with only 4 certifications.

The bug was confirmed by an unresolved fork on the 02/01/2020.

Might be related to #1393.

see :

• https://forum.duniter.org/t/ancien-membre-de-retour-avec-seulement-4-certifications/6712
• https://forum.duniter.org/t/bloquage-g1-le-02-01-2020/6719