Change centering of map you see when registering data collector

[cathinkaw]

When registering a data collector there is a map.

• If the browser gives access to your gps location, the map should be centered on your gps location
• If gps location is not available the maps should be centered on the african continent. (ie something like this view https://www.google.com/maps/@-0.2737178,21.7762443,4.04z)