docker: don't copy id_rsa in agent-debian

This file isn't generated anymore so throws an error
when it is tried to be copied to authorised_keys.

Change-Id: I1cad8e2315b93d645f71f802c98428056e4ed678
diff --git a/jenkins-docker/agent-debian/Dockerfile b/jenkins-docker/agent-debian/Dockerfile
index 6bea15d..e22b7a7 100644
--- a/jenkins-docker/agent-debian/Dockerfile
+++ b/jenkins-docker/agent-debian/Dockerfile
@@ -53,9 +53,6 @@
 RUN chown -R jenkins:jenkins /home/jenkins/.ssh
 RUN chmod -R 700 /home/jenkins/.ssh
 
-COPY id_rsa.pub /home/jenkins/.ssh/authorized_keys
-RUN chown jenkins:jenkins /home/jenkins/.ssh/authorized_keys
-
 COPY gitconfig $JENKINS_REF/.gitconfig
 
 RUN mkdir /var/run/sshd
diff --git a/jenkins-docker/agent-debian/Makefile b/jenkins-docker/agent-debian/Makefile
index 164b36b..cbe2903 100644
--- a/jenkins-docker/agent-debian/Makefile
+++ b/jenkins-docker/agent-debian/Makefile
@@ -5,7 +5,7 @@
 GIT_VER=2.26.2
 DEBIAN_VER=buster
 
-build:  id_rsa.pub
+build:
 	@echo "Building Docker for Debian:$(DEBIAN_VER)"
 	@echo "========================================"
 	cat Dockerfile | DEBIAN_VER=$(DEBIAN_VER) MAVEN_VER=$(MAVEN_VER) GIT_VER=$(GIT_VER) envsubst > Dockerfile-$(DEBIAN_VER)
@@ -14,11 +14,7 @@
 publish:
 	docker push ${IMAGE}:$(DEBIAN_VER)
 
-id_rsa.pub: ../server/id_rsa.pub
-	cp $? $@
-
 clean:
 	docker rmi -f ${IMAGE}
-	-rm -f id_rsa*
 
-.PHONY: clean id_rsa.pub publish
+.PHONY: clean publish