Only set query field when appropriate query param passed via URL

- Setting query value to default option when query param wasn't
  passed via URL was overriding placeholder text in query field

- We wanted placeholder text in field, not the query field to actually
  be populated by placeholder text

- This clears field when user starts typing query into the query field,
  instead of them having to manually delete the  default text populated

src/interface/web/index.html

@@ -85,7 +85,10 @@
         // Fill search form with values passed in URL query parameters, if any.
         window.onload = function () {
             document.getElementById("type").value = new URLSearchParams(window.location.search).get("t") || "org";
-            document.getElementById("query").value = new URLSearchParams(window.location.search).get("q") || "What is the meaning of life?";
+            var query_via_url = new URLSearchParams(window.location.search).get("q");
+            if (query_via_url) {
+                document.getElementById("query").value = query_via_url;
+            }
         }
     </script>