docker: fix Bionic (Ubuntu 18.04) support

docker/DockerfileDepsBionic

@@ -6,6 +6,7 @@ RUN echo "APT::Acquire::Retries \"3\";" > /etc/apt/apt.conf.d/80-retries
 RUN apt-get update && apt-get install -y \
         apt-transport-https build-essential pkg-config git wget libncurses5-dev libreadline-dev nettle-dev \
         libgnutls28-dev libuv1-dev cython3 python3-dev python3-setuptools libcppunit-dev libjsoncpp-dev \
+        libargon2-0-dev \
         autotools-dev autoconf libfmt-dev libhttp-parser-dev libmsgpack-dev libssl-dev python3-pip \
     && apt-get clean && rm -rf /var/lib/apt/lists/* /var/cache/apt/*
 
@@ -21,9 +22,9 @@ RUN echo "** Building a recent version of asio ***" \
 
 RUN echo "*** Downloading RESTinio ***" \
     && mkdir restinio && cd restinio \
-    && wget https://github.com/aberaud/restinio/archive/e0a261dd8488246a3cb8bbb3ea781ea5139c3c94.tar.gz \
-    && ls -l && tar -xzf e0a261dd8488246a3cb8bbb3ea781ea5139c3c94.tar.gz \
-    && cd restinio-e0a261dd8488246a3cb8bbb3ea781ea5139c3c94/dev \
+    && wget https://github.com/aberaud/restinio/archive/8d5d3e8237e0947adb9ba1ffc8281f4ad7cb2a59.tar.gz \
+    && ls -l && tar -xzf 8d5d3e8237e0947adb9ba1ffc8281f4ad7cb2a59.tar.gz \
+    && cd restinio-8d5d3e8237e0947adb9ba1ffc8281f4ad7cb2a59/dev \
     && cmake -DCMAKE_INSTALL_PREFIX=/usr -DRESTINIO_TEST=OFF -DRESTINIO_SAMPLE=OFF \
              -DRESTINIO_INSTALL_SAMPLES=OFF -DRESTINIO_BENCH=OFF -DRESTINIO_INSTALL_BENCHES=OFF \
              -DRESTINIO_FIND_DEPS=ON -DRESTINIO_ALLOW_SOBJECTIZER=Off -DRESTINIO_USE_BOOST_ASIO=none . \