fix: use the appropriate ID when trying to import `github_team_member…

…s` objects (integrations#1074)

When importing a `github_team_member`, the import command passes in team ID as the
"Id", not the "team_id" captured in the state for existing resources, and this empty string is
causing the import step to fail when parsing as a number. Should fix integrations#608, as I hit the same error.

github/resource_github_team_members.go

@@ -185,6 +185,10 @@ func resourceGithubTeamMembersRead(d *schema.ResourceData, meta interface{}) err
 	client := meta.(*Owner).v3client
 	orgId := meta.(*Owner).id
 	teamIdString := d.Get("team_id").(string)
+	if teamIdString == "" && !d.IsNewResource() {
+		log.Printf("[DEBUG] Importing team with id %q", d.Id())
+		teamIdString = d.Id()
+	}
 
 	teamId, err := strconv.ParseInt(teamIdString, 10, 64)
 	if err != nil {