Minor code householding

src/main/java/fr/xephi/authme/command/executable/authme/PurgeCommand.java

@@ -1,5 +1,6 @@
 package fr.xephi.authme.command.executable.authme;
 
+import com.google.common.primitives.Ints;
 import fr.xephi.authme.command.ExecutableCommand;
 import fr.xephi.authme.task.purge.PurgeService;
 import org.bukkit.ChatColor;
@@ -26,10 +27,8 @@ public class PurgeCommand implements ExecutableCommand {
         String daysStr = arguments.get(0);
 
         // Convert the days string to an integer value, and make sure it's valid
-        int days;
-        try {
-            days = Integer.parseInt(daysStr);
-        } catch (NumberFormatException ex) {
+        Integer days = Ints.tryParse(daysStr);
+        if (days == null) {
             sender.sendMessage(ChatColor.RED + "The value you've entered is invalid!");
             return;
         }