Update dependencies

- including overpass-frontend, which had a major release (v3.0.0):
  https://github.com/plepe/overpass-frontend/blob/master/CHANGELOG.md
- overpass-layer (minor release, because of overpass-frontend update)
- revert LeafletJS to 1.7, due to a bug

package.json

@@ -27,7 +27,7 @@
     "ip-location": "^1.0.1",
     "js-yaml": "^4.1.0",
     "json-multiline-strings": "^0.1.0",
-    "leaflet": "^1.9.2",
+    "leaflet": "~1.7",
     "leaflet-geosearch": "^3.7.0",
     "leaflet-polylineoffset": "^1.1.1",
     "leaflet-textpath": "git+https://github.com/makinacorpus/Leaflet.TextPath.git#leaflet0.8-dev",
@@ -44,7 +44,7 @@
     "openstreetmap-date-format": "^0.3.1",
     "openstreetmap-date-parser": "^0.1.2",
     "openstreetmap-tag-translations": "git+https://github.com/plepe/openstreetmap-tag-translations.git",
-    "overpass-frontend": "^2.7.2",
+    "overpass-frontend": "^3.0.0",
     "overpass-layer": "^3.2.1",
     "query-string": "^6.13.8",
     "sheet-router": "^4.2.3",