Fix the way we found the apache/nginx user

If you have another web server like tomcat on your server, the previous command end up returning tomcat instead of apache.

Previously we looked at the whole line, now only at the user and the command name

Author: BenoitLeveque

book/installation.rst

@@ -243,7 +243,7 @@ If there are any issues, correct them now before moving on.
         $ rm -rf app/cache/*
         $ rm -rf app/logs/*
 
-        $ HTTPDUSER=`ps aux | grep -E '[a]pache|[h]ttpd|[_]www|[w]ww-data|[n]ginx' | grep -v root | head -1 | cut -d\  -f1`
+        $ HTTPDUSER=`ps axo user,comm | grep -E '[a]pache|[h]ttpd|[_]www|[w]ww-data|[n]ginx' | grep -v root | head -1 | cut -d\  -f1`
         $ sudo chmod +a "$HTTPDUSER allow delete,write,append,file_inherit,directory_inherit" app/cache app/logs
         $ sudo chmod +a "`whoami` allow delete,write,append,file_inherit,directory_inherit" app/cache app/logs
 
@@ -258,7 +258,7 @@ If there are any issues, correct them now before moving on.
 
     .. code-block:: bash
 
-        $ HTTPDUSER=`ps aux | grep -E '[a]pache|[h]ttpd|[_]www|[w]ww-data|[n]ginx' | grep -v root | head -1 | cut -d\  -f1`
+        $ HTTPDUSER=`ps axo user,comm | grep -E '[a]pache|[h]ttpd|[_]www|[w]ww-data|[n]ginx' | grep -v root | head -1 | cut -d\  -f1`
         $ sudo setfacl -R -m u:"$HTTPDUSER":rwX -m u:`whoami`:rwX app/cache app/logs
         $ sudo setfacl -dR -m u:"$HTTPDUSER":rwX -m u:`whoami`:rwX app/cache app/logs