Fixed conditional

src/main/java/org/scribe/model/OAuthRequest.java

@@ -41,13 +41,14 @@ public class OAuthRequest extends Request
 
   private String checkKey(String key)
   {
-    if (!key.startsWith(OAUTH_PREFIX) || !key.equals(OAuthConstants.SCOPE))
+    if (key.startsWith(OAUTH_PREFIX) || key.equals(OAuthConstants.SCOPE))
-    {
-      throw new IllegalArgumentException(String.format("OAuth parameters must either be %s or start with '%s'", OAuthConstants.SCOPE, OAUTH_PREFIX));
-    } else
     {
       return key;
     } 
+    else
+    {
+      throw new IllegalArgumentException(String.format("OAuth parameters must either be '%s' or start with '%s'", OAuthConstants.SCOPE, OAUTH_PREFIX));
+    }
   }
 
   /**