bug fix in Dockerfile

Dockerfile

@@ -59,7 +59,8 @@ RUN chown -R root:root /opt/shibboleth/shibboleth-identity-provider-$version &&
     rm -rf /usr/local/tomcat/webapps/* && \
     ANT_OPTS="-Didp.target.dir=/opt/shibboleth/current" /opt/shibboleth/current/bin/build.sh && \
     ln -s /opt/shibboleth/current /opt/shibboleth-idp && \
-    ln -s /opt/shibboleth-idp/war/idp.war $CATALINA_HOME/webapps/idp.war
+    ln -s /opt/shibboleth-idp/war/idp.war $CATALINA_HOME/webapps/idp.war && \ 
+	mkdir -p /opt/shibboleth/shibboleth-identity-provider-$VERSION/edit-webapp
 
 # for a mounted config
 VOLUME ["/usr/local/tomcat/conf", \