settings: use cached Git config entries for unscoped vars

Use the cached copy of Git configuration entries not only for URL-scoped
keys, but unscoped keys too!

Author: mjcheetham

src/shared/Core/Settings.cs

@@ -429,7 +429,9 @@ public IEnumerable<string> GetSettingValues(string envarName, string section, st
                  *        property = value
                  *
                  */
-                if (config.TryGet($"{section}.{property}", isPath, out value))
+                string name = $"{section}.{property}";
+                if ((isPath && config.TryGet(name, isPath, out value)) ||
+                    configEntries.TryGetValue(name, out value))
                 {
                     yield return value;
                 }