Modify maxCarbEntryFutureTime to 4 hours

[marionbarker]

Many people use future carb entry to handle fat and protein rise. I believe increasing this value from 1 hour to 4 hours is a reasonable compromise between safety and convenience.

Note:

• This is a personal opinion
• I use 4 hours when dosing for my evening meal
  • I enter a prompt meal entry and future fat/protein rise entry at the same time
  • I am able to do this because I customized my code