[uMap] Update the map and zoom center

[Michel Roche]

Hello,
I noticed that since some time the center of the map isn't updating even 
when we save the center and zoom of the map from the edition zone.

When showing the map via an iframe, the center is still some days and 
saves ago, but changes from time to time...

So it leads me to ask if there's maybe a cache issue, not refreshing as 
often as we could dream, or if there's a bug in clearing the map cache 
when saving the new center.

Example of map :
https://umap.openstreetmap.fr/fr/map/le-trajet-des-pipelettes-a-bicyclette_1013176

redirects to : 
https://umap.openstreetmap.fr/fr/map/le-trajet-des-pipelettes-a-bicyclette_1013176#12/41.6816/8.9598

whereas I saved :
https://umap.openstreetmap.fr/fr/map/le-trajet-des-pipelettes-a-bicyclette_1013176#12/41.9121/9.1104
for example

No matter if I look at the map directly on umap.openstreetmap.fr or via 
an iframe

Do some of you have the same problem ?

Michel