Add regex support to restricted users ip addresses #1227

Seems to work: https://regex101.com/r/zSp6Ke/1
@ljacqu What do you think?

src/main/java/fr/xephi/authme/service/ValidationService.java

@@ -157,8 +157,25 @@ public class ValidationService implements Reloadable {
 
         String ip = PlayerUtils.getPlayerIp(player);
         String domain = player.getAddress().getHostName();
-        return restrictions.stream()
-            .anyMatch(restriction -> ip.equals(restriction) || domain.equalsIgnoreCase(restriction));
+        for(String restriction : restrictions) {
+            if(restriction.startsWith("regex:")) {
+                restriction = restriction.replace("regex:", "");
+                if(ip.matches(restriction)) {
+                    return true;
+                }
+                if(domain.matches(restriction)) {
+                    return true;
+                }
+            } else {
+                if(ip.equals(restriction)) {
+                    return true;
+                }
+                if(domain.equalsIgnoreCase(restriction)) {
+                    return true;
+                }
+            }
+        }
+        return false;
     }
 
     /**

src/main/java/fr/xephi/authme/settings/properties/RestrictionSettings.java

@@ -78,9 +78,11 @@ public final class RestrictionSettings implements SettingsHolder {
     @Comment({
         "The restricted user feature will kick players listed below",
         "if they don't match the defined IP address. Names are case-insensitive.",
+        "Ip addresses support regex expressions (regex:127\\.0\\.0\\..*)",
         "Example:",
         "    AllowedRestrictedUser:",
-        "    - playername;127.0.0.1"})
+        "    - playername;127.0.0.1",
+        "    - playername;regex:127\\.0\\.0\\..*"})
     public static final Property<List<String>> RESTRICTED_USERS =
         newLowercaseListProperty("settings.restrictions.AllowedRestrictedUser");