try to fix java install issue

backend/scripts/install.sh

@@ -0,0 +1,17 @@
+#/bin/bash
+
+# install node.js
+if [ "${CRAWLAB_SERVER_LANG_NODE}" = "Y" ];
+then
+	echo "installing node.js"
+	/bin/sh /app/backend/scripts/install-nodejs.sh
+	echo "installed node.js"
+fi
+
+# install java
+if [ "${CRAWLAB_SERVER_LANG_JAVA}" = "Y" ];
+then
+	echo "installing java"
+	/bin/sh /app/backend/scripts/install-java.sh
+	echo "installed java"
+fi