Fixes issue with failed silent auth

Batch Explorer would not start when an exception is thrown during silent auth that isn't an authentication error.

src/client/core/aad/auth-provider.spec.ts

@@ -156,6 +156,28 @@ describe("AuthProvider", () => {
         expectRetryable(["50071", "50133"], false); // One retryable, one not
 
     });
+
+    it("shouldn't fail with non-auth exception", async () => {
+        spyOn<any>(authProvider, "_createClient").and.callFake(tenantId => {
+            const spy = makeClientApplicationSpy();
+            returnToken(spy.acquireTokenByCode, `${tenantId}-token`);
+            return spy;
+        });
+        const authCodeSpy =
+            jasmine.createSpy("authCodeCallback").and.returnValues(
+                Promise.reject(new Error("Non-auth error")),
+            );
+
+        try {
+            await authProvider.getToken({
+                tenantId: "tenant1",
+                resourceURI: "resourceURI1",
+                authCodeCallback: authCodeSpy
+            });
+        } catch (e) {
+            fail(`Should not have thrown error: ${e}`);
+        }
+    });
 });
 
 const makeTokenCacheSpy = () => jasmine.createSpyObj(

src/client/core/aad/auth-provider.ts

@@ -101,7 +101,9 @@ export default class AuthProvider {
                 );
                 code = await authCodeCallback(url, tenantId, true);
             } catch (silentAuthException) {
-                if (!this._isTenantAuthRetryable(silentAuthException)) {
+                log.debug(`[${tenantId}] Silent auth failed (${silentAuthException})`)
+                if (silentAuthException instanceof AuthorizeError &&
+                    !this._isTenantAuthRetryable(silentAuthException)) {
                     log.warn(`Fatal authentication exception for ${tenantId}:` +
                         ` ${silentAuthException} (non-retryable error code ` +
                         silentAuthException.errorCodes.join(";") + `)`);