Web crawl command: improve exception; do not fail on empty <loc> in sitemap

import/xsl/sitemap.xsl

@@ -9,7 +9,7 @@
         <add>
             <xsl:for-each select="//sitemap:url">
                 <!-- We can't index without a loc element containing a URI! -->
-                <xsl:if test="sitemap:loc">
+                <xsl:if test="string-length(sitemap:loc) > 0">
                     <doc>
                         <!-- Pass the URI to PHP, which will use full-text
                              extraction and generate pre-built XML output;

module/VuFindConsole/src/VuFindConsole/Command/Import/WebCrawlCommand.php

@@ -364,7 +364,7 @@ protected function harvestSitemap(
                     }
                 } catch (\Exception $e) {
                     if ($verbose) {
-                        $output->writeln($e::class . ': ' . $e->getMessage());
+                        $output->writeln((string)$e);
                     }
                     $retVal = false;
                 }