Fix - install missing unzip program

The reason for the change:
"As there is no 'unzip' nor '7z' command installed zip files are being unpacked using the PHP zip extension.
This may cause invalid reports of corrupted archives. Besides, any UNIX permissions (e.g. executable) defined in the archives will be lost.
Installing 'unzip' or '7z' (21.01+) may remediate them."

.docker/images/wordpress/Dockerfile

@@ -10,8 +10,7 @@ ARG SERVER_NAME
 
 # Install sudo in order to run wp-cli as the www-data user 
 # install mysql client, text editors
-RUN apt-get update && apt-get install -y sudo less \ 
-default-mysql-client nano vim
+RUN apt-get update && apt-get install -y sudo less default-mysql-client nano vim unzip
 
 # Install WP-CLI 
 RUN curl -o /bin/wp-cli.phar https://raw.githubusercontent.com/wp-cli/builds/gh-pages/phar/wp-cli.phar

.docker/images/wordpress/Dockerfile-ssl

@@ -8,8 +8,7 @@ ARG BASEDIR
 
 # Install sudo in order to run wp-cli as the www-data user 
 # install mysql client, text editors
-RUN apt-get update && apt-get install -y sudo less \ 
-default-mysql-client nano vim
+RUN apt-get update && apt-get install -y sudo less default-mysql-client nano vim unzip
 
 # Install WP-CLI 
 RUN curl -o /bin/wp-cli.phar https://raw.githubusercontent.com/wp-cli/builds/gh-pages/phar/wp-cli.phar