Drop the useless PHP tokenizer extension install step (laradock#1650)

It is bundled and enabled by default in the PHP language already, and adding this step raises a warning:
warning: tokenizer (tokenizer.so) is already loaded!

Also if this option disabled, it's still installed as part of the language anyway!

Author: Omranic

docker-compose.yml

@@ -143,7 +143,6 @@ services:
           - INSTALL_MYSQLI=${PHP_FPM_INSTALL_MYSQLI}
           - INSTALL_PGSQL=${PHP_FPM_INSTALL_PGSQL}
           - INSTALL_PG_CLIENT=${PHP_FPM_INSTALL_PG_CLIENT}
-          - INSTALL_TOKENIZER=${PHP_FPM_INSTALL_TOKENIZER}
           - INSTALL_INTL=${PHP_FPM_INSTALL_INTL}
           - INSTALL_GHOSTSCRIPT=${PHP_FPM_INSTALL_GHOSTSCRIPT}
           - INSTALL_LDAP=${PHP_FPM_INSTALL_LDAP}

env-example

@@ -134,7 +134,6 @@ WORKSPACE_SSH_PORT=2222
 PHP_FPM_INSTALL_ZIP_ARCHIVE=true
 PHP_FPM_INSTALL_BCMATH=true
 PHP_FPM_INSTALL_MYSQLI=true
-PHP_FPM_INSTALL_TOKENIZER=true
 PHP_FPM_INSTALL_INTL=true
 PHP_FPM_INSTALL_IMAGEMAGICK=true
 PHP_FPM_INSTALL_OPCACHE=true

php-fpm/Dockerfile

@@ -392,15 +392,6 @@ RUN if [ ${INSTALL_MYSQLI} = true ]; then \
     docker-php-ext-install mysqli \
 ;fi
 
-###########################################################################
-# Tokenizer Modifications:
-###########################################################################
-
-ARG INSTALL_TOKENIZER=false
-
-RUN if [ ${INSTALL_TOKENIZER} = true ]; then \
-    docker-php-ext-install tokenizer \
-;fi
 
 ###########################################################################
 # Human Language and Character Encoding Support: