Spelling error corrected usefull -> useful

diff --git a/PokemonGo/RocketAPI/Window/MainForm.cs b/PokemonGo/RocketAPI/Window/MainForm.cs
index a767e01..85f18f5 100644
--- a/PokemonGo/RocketAPI/Window/MainForm.cs
+++ b/PokemonGo/RocketAPI/Window/MainForm.cs
@@ -250,7 +250,7 @@ namespace PokemonGo.RocketAPI.Window
                 await Task.Delay(5000);
                 PrintLevel(client);
                 await ExecuteFarmingPokestopsAndPokemons(client);
-                ColoredConsoleWrite(Color.Red, $"No nearby usefull locations found. Please wait 10 seconds.");
+                ColoredConsoleWrite(Color.Red, $"No nearby useful locations found. Please wait 10 seconds.");
                 await Task.Delay(10000);
                 CheckVersion();
                 Execute();