[Rise of Kingdoms] Gather Gem Enhancement

Hi, for now gather gem function works on steps:

1. find gem
2. send march
3. repeat until no more march or reach distance

My enhancement suggestion is adding a check if all marches already is unavailable. Here are the steps:

1. find gem
2. send march
3. check if there is march available or not.
4. repeat until no more march or reach distance