Clarify Content Cafe code/comments.

config/vufind/config.ini

@@ -991,12 +991,12 @@ timeout = 10
 url = "https://api.booksite.com"
 ;key = "Key"
 
-; You can change the base Content Cafe URL used by the content services here.  Most
-; users will not need to change this setting.  You also need to set your password,
-; "pw".  Note that Content Cafe is a subscription service from Baker & Taylor.
+; Content Cafe is a subscription service from Baker & Taylor. If you are using this
+; service (see the [Content] section above for details), you MUST uncomment and set
+; the password (pw) setting. You may also change the API base URL (url) if needed.
 [Contentcafe]
-url              = "http://contentcafe2.btol.com"
-pw               = "Password"
+;url              = "http://contentcafe2.btol.com"
+;pw               = "Password"
 
 ; Summon is optional; this section is used for your API credentials. apiId is the
 ; short, human-readable identifier for your Summon account; apiKey is the longer,

module/VuFind/src/VuFind/Content/Covers/ContentCafe.php

@@ -60,8 +60,7 @@ class ContentCafe extends \VuFind\Content\AbstractCover
     public function __construct(\Zend\Config\Config $config)
     {
         $this->password = $config->pw;
-        $this->baseURL = isset($config->url)
-            ? $config->url : 'http://contentcafe2.btol.com';
+        $this->baseURL = $config->url ?? 'http://contentcafe2.btol.com';
         $this->supportsUpc = $this->supportsIsbn = $this->cacheAllowed = true;
     }