docker: drop removed --miner.threads flag usage

Signed-off-by: Jakub Sokołowski <jakub@status.im>

defaults/main.yml

@@ -87,7 +87,6 @@ geth_bootnodes: []
 
 # Mining settings
 geth_miner_enabled: false
-geth_miner_threads: '{{ ansible_processor_vcpus }}'
 geth_miner_account: '{{ geth_account_addr }}'
 
 # Whisper protocol

templates/docker-compose.yml.j2

@@ -50,7 +50,6 @@ services:
 {% endif %}
 {% if geth_miner_enabled %}
       --mine
-      --miner.threads="{{ geth_miner_threads }}"
       --miner.etherbase="{{ geth_miner_account | mandatory }}"
 {% endif %}
 {% if geth_whisper_enabled %}