Spelling improvement

***no_ci***

Author: networkfusion

Diff for: samples/Json/JsonConfigurationStore/Program.cs

@@ -22,10 +22,10 @@ public static void Main()
                 Setting3 = "Setting 3 value"
             };
 
-            Debug.WriteLine($"A configuration file does {(configurationStore.IsConfigFileExisting ? string.Empty : "not ")} exists.");
+            Debug.WriteLine($"A configuration file does {(configurationStore.IsConfigFileExisting ? string.Empty : "not ")} exist.");
             configurationStore.ClearConfig();
             Debug.WriteLine("The configuration file has been deleted.");
-            Debug.WriteLine($"A configuration file does {(configurationStore.IsConfigFileExisting ? string.Empty : "not ")} exists.");
+            Debug.WriteLine($"A configuration file does {(configurationStore.IsConfigFileExisting ? string.Empty : "not ")} exist.");
 
             Debug.WriteLine("Saving configuration file");
             var writeResult = configurationStore.WriteConfig(configuration);