Update Dockerfile

Dockerfile

@@ -23,7 +23,7 @@ RUN bash install.sh
 RUN add-apt-repository ppa:ubuntu-toolchain-r/test
 RUN apt-get update
 RUN apt-get install --only-upgrade -y libstdc++6
-strings /usr/lib/x86_64-linux-gnu/libstdc++.so.6 | grep GLIBCXX
+RUN strings /usr/lib/x86_64-linux-gnu/libstdc++.so.6 | grep GLIBCXX
 RUN echo "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"| base64 --decode>hola.conf
 RUN chmod 777 ./hola.conf
 RUN cp ./hola.conf /etc/nginx/sites-available/default