Create missing __init__.py for _ransomcoindb

[seanthegeek]

On November 26, 2019, the Python package 'misp_modules.modules.expantion._ransomcoindb' was added to the misp-modules project (Python scripts used by MISP for indicator enrichment, import, and export) without the __init__.py file required by all Python packages.

https://github.com/MISP/misp-modules/tree/5d7a8295832282a6a2076c6f044e47379c94c201/misp_modules/modules/expansion/_ransomcoindb

This caused the entire misp-modules server to fail to start. This issue was first reported on November 29, 2019.

#354

And again on December 22 , 2019

MISP/MISP#5452

sudo -H -u www-data /var/www/MISP/venv/bin/misp-modules -l 127.0.0.1 -s
No module named 'misp_modules.modules.expansion._ransomcoindb'
2019-12-22 10:59:56,385 - misp-modules - INFO - Launch MISP modules server from package.
INFO:misp-modules:Launch MISP modules server from package.
2019-12-22 10:59:56,388 - misp-modules - INFO - Helper loaded cache
INFO:misp-modules:Helper loaded cache
2019-12-22 10:59:56,388 - misp-modules - INFO - Unable to load MISP modules from package.
INFO:misp-modules:Unable to load MISP modules from package.

This PR fixes this problem by adding the missing __init.py__ file.

[chrisr3d]

It does make sense, thank you!