Update databaseFetcher.ts

Made suggested changes; comments can be found at github#961

Author: mgsium

extensions/ql-vscode/src/databaseFetcher.ts

@@ -454,10 +454,11 @@ export async function convertToDatabaseUrl(
     let projectJson = await downloadLgtmProjectMetadata(lgtmUrl);
 
     if (projectJson.code === 404) {
-      // fallback check for github repos with same name but different case
+      // fallback check for github repositories with same name but different case
+      // will fail for other providers
       let canonicalName = await retrieveCanonicalRepoName(lgtmUrl);
       if (!canonicalName) {
-        throw new Error('Repository not found.');
+        throw new Error(`Project was not found at ${lgtmUrl}.`);
       }
       canonicalName = convertRawLgtmSlug(`g/${canonicalName}`);
       projectJson = await downloadLgtmProjectMetadata(canonicalName);