Fix test skip mechanism to handle empty env vars

The ifEnvVarNotSet function was only checking for undefined, but in CI
environments variables can be set to empty strings. This caused tests
to run when they should have been skipped, resulting in 401 errors.

Now checks for both undefined and empty string values.

Co-authored-by: Ona <[email protected]>

Author: geropl

components/gitpod-protocol/src/util/skip-if.ts

@@ -5,13 +5,14 @@
  */
 
 /**
- * Skips a Mocha TestSuite if a certain env var is not set and prints its
+ * Skips a Mocha TestSuite if a certain env var is not set or empty
  * @param name The name of the env var the TestSuite depends on being present
  */
 export function ifEnvVarNotSet(name: string): boolean {
-    const skip = process.env[name] === undefined;
+    const value = process.env[name];
+    const skip = value === undefined || value === "";
     if (skip) {
-        console.log(`Skipping suite because env var '${name}' is not set`);
+        console.log(`Skipping suite because env var '${name}' is not set or empty`);
     }
     return skip;
 }