Use formatting print to show underlying error message (#500)

* Use formatting print to show underlying error message

This appears to be a typo where "Println" was used instead of "Printf"

Signed-off-by: Kenny Root <kenny@the-b.org>

* Update collector/collector.go

---------

Signed-off-by: Kenny Root <kenny@the-b.org>
Co-authored-by: Ettore Di Giacinto <mudler@users.noreply.github.com>

collector/collector.go

@@ -464,7 +464,12 @@ func fetchRemoteConfig(url string) (*Config, error) {
 
 	if !HasValidHeader(string(body)) {
 		// TODO: Print a warning when we implement proper logging
-		fmt.Println("No valid header in remote config: %w", err)
+                if err != nil {
+		   fmt.Printf("No valid header in remote config: %s\n", err.Error())
+		} else {
+       	   fmt.Println("No valid header in remote config")
+       	 }
+
 		return result, nil
 	}