Remove php8-sysvmsg and update README

> To enable the System V messages support compile PHP with the option --enable-sysvmsg.
>
> https://www.php.net/manual/en/sem.installation.php#sem.installation

Author: macbre

Dockerfile

@@ -38,7 +38,6 @@ RUN apk update && apk add \
 	php8-soap \
 	php8-sockets \
 	php8-sodium \
-	php8-sysvmsg \
 	php8-sysvsem \
 	php8-sysvshm \
 	php8-xmlreader \

README.md

@@ -22,13 +22,13 @@ $ docker run -it elecena/python-php sh info.sh
 
 ### Python
 Python 3.9.0
-virtualenv 20.0.33 from /usr/local/lib/python3.9/site-packages/virtualenv/__init__.py
+virtualenv 20.2.2 from /usr/local/lib/python3.9/site-packages/virtualenv/__init__.py
 
 ### PHP
-PHP 7.4.9 (cli) (built: Aug 31 2020 19:20:23) ( NTS )
+PHP 8.0.0 (cli) (built: Dec  4 2020 00:28:56) ( NTS )
 Copyright (c) The PHP Group
-Zend Engine v3.4.0, Copyright (c) Zend Technologies
-    with Zend OPcache v7.4.9, Copyright (c), by Zend Technologies
+Zend Engine v4.0.0-dev, Copyright (c) Zend Technologies
+    with Zend OPcache v8.0.0, Copyright (c), by Zend Technologies
 Composer version 1.10.13 2020-09-09 11:46:34
 [PHP Modules]
 bz2
@@ -64,7 +64,6 @@ sockets
 sodium
 SPL
 standard
-sysvmsg
 sysvsem
 sysvshm
 tokenizer