envUtils.ts: log envFile load error

This will turn ambiguous messages like this:
<img width="269" alt="image" src="https://user-images.githubusercontent.com/51177946/164947223-a890fbfc-2658-4a6a-88bc-c3e27908cd4b.png">
into this:
<img width="266" alt="image" src="https://user-images.githubusercontent.com/51177946/164947521-57f8ed07-e3ca-4bd5-b2cd-28e2e40e2121.png">

Change-Id: Ic8c3edc6fea9488e92d293826cefef6bcb018582
GitHub-Last-Rev: 2a2ea1fba7020d5e4fee7fd1be180293a8438b38
GitHub-Pull-Request: golang/vscode-go#2210
Reviewed-on: https://go-review.googlesource.com/c/vscode-go/+/401994
Reviewed-by: Hyang-Ah Hana Kim <hyangah@gmail.com>
Run-TryBot: Hyang-Ah Hana Kim <hyangah@gmail.com>
Auto-Submit: Hyang-Ah Hana Kim <hyangah@gmail.com>
TryBot-Result: kokoro <noreply+kokoro@google.com>
Reviewed-by: Jamal Carvalho <jamal@golang.org>
diff --git a/src/utils/envUtils.ts b/src/utils/envUtils.ts
index bb5166a..81b6f55 100644
--- a/src/utils/envUtils.ts
+++ b/src/utils/envUtils.ts
@@ -39,7 +39,7 @@
 		});
 		return env;
 	} catch (e) {
-		throw new Error(`Cannot load environment variables from file ${envFilePath}`);
+		throw new Error(`Cannot load environment variables from file ${envFilePath}: ${e}`);
 	}
 }