Change: Use SERVER_HOSTNAME instead of HOSTNAME

Dockerfile

@@ -63,7 +63,7 @@ ENV VPNSP=pia \
     # Mullvad, PureVPN, Windscribe only
     CITY= \
     # Windscribe only
-    HOSTNAME= \
+    SERVER_HOSTNAME= \
     # Mullvad only
     ISP= \
     OWNED=no \

internal/params/privado.go

@@ -2,10 +2,13 @@ package params
 
 import (
 	"github.com/qdm12/gluetun/internal/constants"
+	libparams "github.com/qdm12/golibs/params"
 )
 
 // GetPrivadoHostnames obtains the hostnames for the Privado server from the
-// environment variable HOSTNAME.
+// environment variable SERVER_HOSTNAME.
 func (r *reader) GetPrivadoHostnames() (hosts []string, err error) {
-	return r.envParams.GetCSVInPossibilities("HOSTNAME", constants.PrivadoHostnameChoices())
+	return r.envParams.GetCSVInPossibilities("SERVER_HOSTNAME",
+		constants.PrivadoHostnameChoices(),
+		libparams.RetroKeys([]string{"HOSTNAME"}, r.onRetroActive))
 }

internal/params/windscribe.go

@@ -21,9 +21,12 @@ func (r *reader) GetWindscribeCities() (cities []string, err error) {
 }
 
 // GetWindscribeHostnames obtains the hostnames for the Windscribe servers from the
-// environment variable HOSTNAME.
+// environment variable SERVER_HOSTNAME.
 func (r *reader) GetWindscribeHostnames() (hostnames []string, err error) {
-	return r.envParams.GetCSVInPossibilities("HOSTNAME", constants.WindscribeHostnameChoices())
+	return r.envParams.GetCSVInPossibilities("SERVER_HOSTNAME",
+		constants.WindscribeHostnameChoices(),
+		libparams.RetroKeys([]string{"HOSTNAME"}, r.onRetroActive),
+	)
 }
 
 // GetWindscribePort obtains the port to reach the Windscribe server on from the