[classifier] Added post_office=post_partner.

Signed-off-by: Viktor Govako <viktor.govako@gmail.com>

data/styles/default/include/Icons.mapcss

@@ -800,6 +800,7 @@ node|z17-[amenity=motorcycle_rental],
 node|z17-[amenity=bicycle_rental],
 node|z17-[amenity=bicycle_repair_station],
 node|z17-[amenity=post_office],
+node|z18-[post_office=post_partner],
 node|z17-[man_made=works],
 node|z17-[amenity=parcel_locker],
 node|z17-[amenity=public_bath],
@@ -1292,8 +1293,10 @@ node|z18-[amenity=bicycle_repair_station],
 {font-size: 11;}
 
 node|z17-[amenity=post_office],
+node|z18-[post_office=post_partner],
 {icon-image: mail-m.svg;}
 node|z18-[amenity=post_office],
+node|z18-[post_office=post_partner],
 {font-size: 11;}
 node|z18-[amenity=post_box],
 {icon-image: postbox-m.svg;font-size: 11;}

data/styles/default/include/priorities_4_overlays.prio.txt

@@ -1176,6 +1176,7 @@ shop-watches                                        # icon z18- (also has captio
 shop-wholesale                                      # icon z18- (also has caption(optional) z18-)
 === 500
 
+post_office-post_partner
 amenity-shower                                      # icon z17- (also has caption(optional) z17-)
 amenity-toilets                                     # icon z18- (also has caption(optional) z18-)
 man_made-embankment                                 # pathtext z18- (also has line z16-)