If you'd like to see ConnectBot translated into your language and you're willing to help, then head on over to https://translations.launchpad.net/connectbot/trunk/+pots/fortune
To compile ConnectBot using gradlew, you must first specify where your Android SDK is via the ANDROID_SDK_HOME environment variable.
To run the Jenkins CI pipeline locally, you can use
jenkinsfile-runner
which can be invoked like this:
docker run -it -v $(pwd):/workspace \
-v jenkinsfile-runner-cache:/var/jenkinsfile-runner-cache \
-v jenkinsfile-runner:/var/jenkinsfile-runner \
-v /var/run/docker.sock:/var/run/docker.sock \
-v $(which docker):$(which docker) \
jenkins/jenkinsfile-runner