Make page mode toggling predictable

Previously, toggling page mode would jump to near page, but usually
not the one your were looking at before.

zathura/shortcuts.c

@@ -1224,6 +1224,8 @@ sc_toggle_page_mode(girara_session_t* session, girara_argument_t*
     return false;
   }
 
+  unsigned int page_id = zathura_document_get_current_page_number(zathura->document);
+
   int pages_per_row = 1;
   girara_setting_get(zathura->ui.session, "pages-per-row", &pages_per_row);
 
@@ -1237,6 +1239,10 @@ sc_toggle_page_mode(girara_session_t* session, girara_argument_t*
   girara_setting_set(zathura->ui.session, "pages-per-row", &value);
   adjust_view(zathura);
 
+  page_set(zathura, page_id);
+  render_all(zathura);
+  refresh_view(zathura);
+
   return true;
 }