Stip leading & trailing whitespace from description.

misc-scripts/xref_mapping/XrefParser/UniProtParser.pm

@@ -183,9 +183,13 @@ sub create_xrefs {
     my $description;
     foreach my $line (@all_lines) {
       my ($description_only) = $line =~ /^DE\s+(.+)/;
-      $description .= " " . $description_only if ($description_only);
+      $description .= $description_only if ($description_only);
+      $description .= " ";
     }
 
+    $description =~ s/^\s*//g;
+    $description =~ s/\s*$//g;
+
     $xref->{DESCRIPTION} = $description;
 
     # extract sequence