Remove versions from dependencies in Dockerfile.

Dockerfile

@@ -4,10 +4,10 @@ WORKDIR ${APACHE_DOCUMENT_ROOT}
 
 RUN apt update && \
     apt install -y \
-    libicu-dev=67.1-7 \
-    libgd-dev=2.3.0-2 \
-    libonig-dev=6.9.6-1.1 \
-    unzip=6.0-26 && \
+    libicu-dev \
+    libgd-dev \
+    libonig-dev \
+    unzip && \
     apt purge -y --auto-remove && \
     apt-get clean && \
     rm -rf /var/lib/apt/lists/* /tmp/* /var/tmp/* /usr/share/doc/*