Run tests with unmodified config-example-test.yaml file

Index: cmd/headscale/headscale_test.go
--- cmd/headscale/headscale_test.go.orig
+++ cmd/headscale/headscale_test.go
@@ -42,7 +42,7 @@ func (*Suite) TestConfigFileLoading(c *check.C) {
 
 	// Symlink the example config file
 	err = os.Symlink(
-		filepath.Clean(path+"/../../config-example.yaml"),
+		filepath.Clean(path+"/../../config-example-test.yaml"),
 		cfgFile,
 	)
 	if err != nil {
@@ -84,7 +84,7 @@ func (*Suite) TestConfigLoading(c *check.C) {
 
 	// Symlink the example config file
 	err = os.Symlink(
-		filepath.Clean(path+"/../../config-example.yaml"),
+		filepath.Clean(path+"/../../config-example-test.yaml"),
 		filepath.Join(tmpDir, "config.yaml"),
 	)
 	if err != nil {
