Updates to #22 Read the api key from app settings regardless if there is a config section.

@ejsmith A end user ran into an issue where they had a config transform
that set the api key and then they were using an azure app setting. When
they did this they occasionally ran into an issue with the api key
already set. I wonder if there is a better way to handle this.. even for
attribute definitions..

Author: niemyjski

Source/Extras/Extensions/ExceptionlessExtraConfigurationExtensions.cs

@@ -76,6 +76,11 @@ public static void ReadAllConfig(this ExceptionlessConfiguration config, params
         /// </summary>
         /// <param name="config">The configuration object you want to apply the attribute settings to.</param>
         public static void ReadFromConfigSection(this ExceptionlessConfiguration config) {
+            // If an appsetting is present for ApiKey, then it will override the other api keys
+            string apiKeyOverride = ConfigurationManager.AppSettings["Exceptionless:ApiKey"];
+            if (IsValidApiKey(apiKeyOverride))
+                config.ApiKey = apiKeyOverride;
+
             ExceptionlessSection section = null;
 
             try {
@@ -89,15 +94,10 @@ public static void ReadFromConfigSection(this ExceptionlessConfiguration config)
 
             config.Enabled = section.Enabled;
 
-            // Only update if it is not null
-            if (!String.IsNullOrEmpty(section.ApiKey) && section.ApiKey != "API_KEY_HERE")
+            // Only update if it hasn't already been set via app settings.
+            if (!IsValidApiKey(apiKeyOverride) && IsValidApiKey(section.ApiKey))
                 config.ApiKey = section.ApiKey;
-
-            // If an appsetting is present for ApiKey, then it will override the other api keys
-            string apiKeyOverride = ConfigurationManager.AppSettings["Exceptionless:ApiKey"] ?? String.Empty;
-            if (!String.IsNullOrEmpty(apiKeyOverride) && apiKeyOverride != "API_KEY_HERE")
-                config.ApiKey = apiKeyOverride;
-
+            
             if (!String.IsNullOrEmpty(section.ServerUrl))
                 config.ServerUrl = section.ServerUrl;
 
@@ -160,5 +160,9 @@ public static void ReadFromConfigSection(this ExceptionlessConfiguration config)
                 }
             }
         }
+
+        private static bool IsValidApiKey(string apiKey) {
+            return !String.IsNullOrEmpty(apiKey) && apiKey != "API_KEY_HERE";
+        }
     }
 }