docker image: fix installation of JDK 8

scripts/setup-ubuntu.sh

@@ -102,6 +102,9 @@ PACKAGES+=" llvm-8-tools"
 # Needed by gitea.
 PACKAGES+=" npm"
 
+# Java.
+PACKAGES+=" openjdk-8-jdk"
+
 # Needed by packages in unstable repository.
 PACKAGES+=" docbook-to-man"
 PACKAGES+=" docbook-utils"
@@ -136,28 +139,6 @@ $SUDO apt-get -yq update
 $SUDO DEBIAN_FRONTEND=noninteractive \
 	apt-get install -yq --no-install-recommends $PACKAGES
 
-# Find and assign UBUNTU_VERSION
-if [[ `lsb_release -rs` == "19.04" ]]; then
-	UBUNTU_VERSION="19.04.2"
-else
-	UBUNTU_VERSION="18.10.1"
-fi
-
-# Make openjdk 8 available:
-curl -O http://security.ubuntu.com/ubuntu/pool/universe/o/openjdk-8/openjdk-8-jdk-headless_8u212-b03-0ubuntu1."$UBUNTU_VERSION"_amd64.deb
-curl -O http://security.ubuntu.com/ubuntu/pool/universe/o/openjdk-8/openjdk-8-jdk_8u212-b03-0ubuntu1."$UBUNTU_VERSION"_amd64.deb
-curl -O http://security.ubuntu.com/ubuntu/pool/universe/o/openjdk-8/openjdk-8-jre_8u212-b03-0ubuntu1."$UBUNTU_VERSION"_amd64.deb
-curl -O http://security.ubuntu.com/ubuntu/pool/universe/o/openjdk-8/openjdk-8-jre-headless_8u212-b03-0ubuntu1."$UBUNTU_VERSION"_amd64.deb
-$SUDO dpkg -i openjdk-8-jre-headless_8u212-b03-0ubuntu1."$UBUNTU_VERSION"_amd64.deb \
-	openjdk-8-jre_8u212-b03-0ubuntu1."$UBUNTU_VERSION"_amd64.deb \
-	openjdk-8-jdk_8u212-b03-0ubuntu1."$UBUNTU_VERSION"_amd64.deb \
-	openjdk-8-jdk-headless_8u212-b03-0ubuntu1."$UBUNTU_VERSION"_amd64.deb || $SUDO apt install -f -y
-
-rm openjdk-8-jre-headless_8u212-b03-0ubuntu1."$UBUNTU_VERSION"_amd64.deb \
-	openjdk-8-jre_8u212-b03-0ubuntu1."$UBUNTU_VERSION"_amd64.deb \
-	openjdk-8-jdk_8u212-b03-0ubuntu1."$UBUNTU_VERSION"_amd64.deb \
-	openjdk-8-jdk-headless_8u212-b03-0ubuntu1."$UBUNTU_VERSION"_amd64.deb
-
 $SUDO locale-gen --purge en_US.UTF-8
 echo -e 'LANG="en_US.UTF-8"\nLANGUAGE="en_US:en"\n' | $SUDO tee -a /etc/default/locale