Correctly check for existing repo in clone dialog.

The clone dialog was validating for the presence of an existing repo at
the destination path, but the validation was dependent upon the
_previous_ validation state. Make sure the current path is always
validated. Fixes #394. Fixes #109.

Author: grokys

src/GitHub.App/ViewModels/RepositoryCloneViewModel.cs

@@ -175,12 +175,8 @@ bool IsAlreadyRepoAtPath(string path)
 
             if (SelectedRepository != null)
             {
-                var validationResult = BaseRepositoryPathValidator.ValidationResult;
-                if (validationResult != null && validationResult.IsValid)
-                {
-                    string potentialPath = Path.Combine(path, SelectedRepository.Name);
-                    isAlreadyRepoAtPath = operatingSystem.Directory.Exists(potentialPath);
-                }
+                string potentialPath = Path.Combine(path, SelectedRepository.Name);
+                isAlreadyRepoAtPath = operatingSystem.Directory.Exists(potentialPath);
             }
 
             return isAlreadyRepoAtPath;