upgraded tomcat to 8.0.52

dockerfiles/Dockerfile.dspace

@@ -34,9 +34,9 @@ ENV LANG=en_US.UTF-8
 ENV LANGUAGE=en_US.UTF-8
 
 # build tomcat 8.0.35, version recommended by LINDAT
-RUN wget -O /tmp/apache-tomcat-8.0.35.tar.gz https://archive.apache.org/dist/tomcat/tomcat-8/v8.0.35/bin/apache-tomcat-8.0.35.tar.gz
+RUN wget -O /tmp/apache-tomcat-8.0.52.tar.gz https://archive.apache.org/dist/tomcat/tomcat-8/v8.0.52/bin/apache-tomcat-8.0.52.tar.gz
 RUN mkdir /opt/tomcat8
-RUN tar xvzf /tmp/apache-tomcat-8.0.35.tar.gz -C /opt/tomcat8/ --strip-components=1
+RUN tar xvzf /tmp/apache-tomcat-8.0.52.tar.gz -C /opt/tomcat8/ --strip-components=1
 RUN groupadd tomcat8
 RUN useradd -s /bin/false -g tomcat8 -d /opt/tomcat8/ tomcat8