use the most recent redis that is compatible with php5

toolset/setup/linux/languages/php.sh

@@ -44,7 +44,7 @@ echo PHP compilation finished, installing extensions
 $PHP_HOME/bin/pecl channel-update pecl.php.net
 # Apc.so
 $PHP_HOME/bin/pecl config-set php_ini $PHP_HOME/lib/php.ini
-printf "\n" | $PHP_HOME/bin/pecl -q install -f redis
+printf "\n" | $PHP_HOME/bin/pecl -q install -f redis-2.2.5
 
 # yaf.so
 # printf "\n" | $PHP_HOME/bin/pecl -q install -f yaf