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: 2a2ea1f
GitHub-Pull-Request: #2210
Reviewed-on: https://go-review.googlesource.com/c/vscode-go/+/401994
Reviewed-by: Hyang-Ah Hana Kim <[email protected]>
Run-TryBot: Hyang-Ah Hana Kim <[email protected]>
Auto-Submit: Hyang-Ah Hana Kim <[email protected]>
TryBot-Result: kokoro <[email protected]>
Reviewed-by: Jamal Carvalho <[email protected]>

Author: polinasok

src/utils/envUtils.ts

@@ -39,7 +39,7 @@ export function parseEnvFile(envFilePath: string): { [key: string]: string } {
 		});
 		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}`);
 	}
 }