Make root pearrc read only.

Author: convissor

README.markdown

@@ -115,6 +115,9 @@ installed version of PHP is the one used by the web server.
 
         wget http://pear.php.net/go-pear.phar
         export PHP_PEAR_PHP_BIN=/usr/local/bin/php
+        sudo echo "#PEAR_Config 0.9" > /root/.pearrc
+        sudo echo "a:0:{}" >> /root/.pearrc
+        sudo chmod 400 /root/.pearrc
         sudo php go-pear.phar
 
     When asked to adjust the configuration: