Pull request: all: fix lint and naming issues vol. 4

Merge in DNS/adguard-home from 2276-fix-lint-4 to master

Updates #2276.

Squashed commit of the following:

commit 15d49184cd8ce1f8701bf3221e69418ca1778b36
Author: Ainar Garipov <A.Garipov@AdGuard.COM>
Date:   Tue Dec 8 15:51:34 2020 +0300

    util: fix naming

commit 3b9a86a0feb8c6e0b167e6e23105e8137b0dda76
Author: Ainar Garipov <A.Garipov@AdGuard.COM>
Date:   Tue Dec 8 15:41:10 2020 +0300

    all: fix lint and naming issues vol. 4

internal/util/network_test.go

@@ -0,0 +1,23 @@
+package util
+
+import (
+	"testing"
+)
+
+func TestGetValidNetInterfacesForWeb(t *testing.T) {
+	ifaces, err := GetValidNetInterfacesForWeb()
+	if err != nil {
+		t.Fatalf("Cannot get net interfaces: %s", err)
+	}
+	if len(ifaces) == 0 {
+		t.Fatalf("No net interfaces found")
+	}
+
+	for _, iface := range ifaces {
+		if len(iface.Addresses) == 0 {
+			t.Fatalf("No addresses found for %s", iface.Name)
+		}
+
+		t.Logf("%v", iface)
+	}
+}