php-fpm, workspace when php5 support old mongo ext. (#1642)

php-fpm/Dockerfile

@@ -160,6 +160,10 @@ ARG INSTALL_MONGO=false
 
 RUN if [ ${INSTALL_MONGO} = true ]; then \
     # Install the mongodb extension
+    if [ $(php -r "echo PHP_MAJOR_VERSION;") = "5" ]; then \
+      pecl install mongo && \
+      docker-php-ext-enable mongo \
+    ;fi && \
     pecl install mongodb && \
     docker-php-ext-enable mongodb \
 ;fi