src/goModules: check goVersion isn't null before using it

Added similar check in goVet - but in such case, the vet
will fail later in runTools.

Fixes #1251

Change-Id: I226a107606e5633584ff1e337efa5762d245099a
Reviewed-on: https://go-review.googlesource.com/c/vscode-go/+/297132
Trust: Hyang-Ah Hana Kim <[email protected]>
Run-TryBot: Hyang-Ah Hana Kim <[email protected]>
TryBot-Result: kokoro <[email protected]>
Reviewed-by: Rebecca Stambler <[email protected]>

Author: hyangah

src/goModules.ts

@@ -58,7 +58,7 @@ export async function getModFolderPath(fileuri: vscode.Uri, isDir?: boolean): Pr
 		return moduleCache;
 	}
 	const goVersion = await getGoVersion();
-	if (goVersion.lt('1.11')) {
+	if (!goVersion || goVersion.lt('1.11')) {
 		return;
 	}
 

src/goVet.ts

@@ -105,7 +105,7 @@ export async function goVet(
 	}
 
 	let vetArgs = ['vet', ...args, ...tagsArg, vetWorkspace ? './...' : '.'];
-	if (goVersion.lt('1.10') && args.length) {
+	if (goVersion && goVersion.lt('1.10') && args.length) {
 		vetArgs = ['tool', 'vet', ...args, ...tagsArg, '.'];
 	}