Update ISSUE_TEMPLATE.md as we don't support 2.x actively anymore
Update ISSUE_TEMPLATE.md as we don't support 2.x actively anymore

hazendaz/assertj-core,hazendaz/assertj-core,assertj/assertj-core,xasx/assertj-core,assertj/assertj-core,xasx/assertj-core,joel-costigliola/assertj-core,joel-costigliola/assertj-core