POSTGIS Postgres Extension (#2110)

* created PHP_FPM_INSTALL_POSTGIS variable
* install postgis if needs
* install_postgis variable

env-example

@@ -169,6 +169,7 @@ PHP_FPM_INSTALL_LDAP=false
 PHP_FPM_INSTALL_PHALCON=false
 PHP_FPM_INSTALL_SWOOLE=false
 PHP_FPM_INSTALL_PG_CLIENT=false
+PHP_FPM_INSTALL_POSTGIS=false
 PHP_FPM_INSTALL_PCNTL=false
 PHP_FPM_INSTALL_CALENDAR=false
 PHP_FPM_INSTALL_FAKETIME=false