Switch to api.openstreetmap.org API host

[danieldegroot2]

Use api.openstreetmap.org/api/ -and HTTPS- instead of www.openstreetmap.org/api/*.

(Is: openstreetmap/operations#951)

cc: @dracos

[codecov]

Codecov Report

Merging #4669 (5395777) into master (71995ab) will decrease coverage by 0.02%.
The diff coverage is n/a.

@@            Coverage Diff             @@
##           master    #4669      +/-   ##
==========================================
- Coverage   85.23%   85.21%   -0.02%     
==========================================
  Files         338      338              
  Lines       23921    23921              
  Branches     4516     4516              
==========================================
- Hits        20389    20385       -4     
- Misses       2164     2166       +2     
- Partials     1368     1370       +2     

Files	Coverage Δ
perllib/FixMyStreet/Geocode/OSM.pm	50.00% <ø> (ø)

... and 2 files with indirect coverage changes

[dracos]

Thanks - looks like only Norway/Sweden could possibly be using this code.