Greg,
On the App/URL Filter tab, go to Applications/Sites --> New --> Category. Name it SSL_Bypass.
Same tab, go to Applications/Sites --> New --> Application/Site. Name it GoToMeeting, click next.
On the next screen, add all of the URLs listed in the following support page:
https://support.logmeininc.com/gotomeeting
Make sure you use wildcards where indicated. On next screen give it a category of SSL_Bypass.
I did not find it necessary to whitelist any of the IPs or ports listed, just the URLs.
Create a rule under HTTPS Inspection policy. Make sure there are NO inspection rules above this bypass rule (all of your bypass rules should be at the top of your policy)
"Some Name" | src:Any | dst:Internet | services: http/https | site category: SSL_Bypass | action: Bypass