Fix a error produced when create entity without enter a location field type and modify this entity after because oldGeo is null

if (newGeo[0] != oldGeo[0] || newGeo[1] != oldGeo[1]) {
		                       ^
TypeError: Cannot read property '0' of undefined
fix issue empty location initialize oldGeo to an empty array if value not exits
Merge pull request #104 from altairstudios/master

Fix a error produced when create entity without enter a location field type