Fix templating error on ansible 2.9.0

[mvdbeek]

Changes

This fixes:

TASK [mtchavez.influxdb : Run config update] *************************************************************
fatal: [gcc-8.training.galaxyproject.eu]: FAILED! => {"msg": "The conditional check 'write_config | changed' failed. The error was: template error while templating string: no filter named 'changed'. String: {% if write_config | changed %} True {% else %} False {% endif %}\n\nThe error appears to be in '/home/ubuntu/galaxy/roles/mtchavez.influxdb/tasks/main.yml': line 58, column 3, but may\nbe elsewhere in the file depending on the exact syntax problem.\n\nThe offending line appears to be:\n\n\n- name: Run config update\n  ^ here\n"

Verify

Run the role on ansible >= 2.9.0

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Add any relevant fixes or closes to reference github issues