Update Dockerfile: Remove OS Repo, since it is already included in the base image

Dockerfile

 FROM opensuse/leap:latest
-RUN zypper ar -f -n OSS http://download.opensuse.org/distribution/leap/15.2/repo/oss/ OSS \
- && zypper install -y git \
+RUN zypper install -y git \
  && zypper install -y unzip \
  && zypper install -y gzip \
  && zypper install -y -t pattern devel_basis devel_C_C++ devel_java \