Don't assume the JRE self-extracter is executable

Dockerfile

@@ -31,7 +31,7 @@ RUN set -x; \
 RUN set -x; \
     mkdir -p /usr/local/java && \
     cd /usr/local/java && \
-    /root/jre-*.bin && \
+    /bin/sh /root/jre-*.bin && \
     echo >>/etc/profile export JRE_HOME=`echo /usr/local/java/jre*` && \
     echo >>/etc/profile export 'PATH="$PATH:$JRE_HOME/bin"' && \
     update-alternatives --install /usr/bin/java   java   /usr/local/java/jre*/bin/java   1 && \