fix #674

For some reason having an empty UL list causes the problem
1.4.6 Cachemanager back button missing title

```cacheImages.php``` missing title for ```Back``` button. Also,
```cacheDBImages.php``` missing space between ```title``` and ```href```
for ```Back``` button.
Merge pull request #690 from JimBrown/1.4.6-Cachemanager

1.4.6 Cachemanager back button missing title
fix #670
Try to convince browsers not to cache setup pages