install ldap module again

Dockerfile

@@ -11,6 +11,7 @@ RUN apt-get update && apt-get install -y \
 	libldap2-dev \
 	&& rm -rf /var/lib/apt/lists/*
 
+RUN docker-php-ext-install ldap
 
 # Enable CGI module
 RUN a2enmod cgi headers rewrite include