Validate LineStrings in uploaded MultiLineString geometry (#1390)
Validate LineStrings in uploaded MultiLineString geometry (#1390)

* Validate LineStrings in uploaded MultiLineString geom

* Rewrite and clear code of GpxUpload validation

c2corg/v6_ui,Courgetteandratatouille/v6_ui,olaurendeau/v6_ui,olaurendeau/v6_ui,olaurendeau/v6_ui,c2corg/v6_ui,Courgetteandratatouille/v6_ui,c2corg/v6_ui,c2corg/v6_ui,olaurendeau/v6_ui,Courgetteandratatouille/v6_ui,Courgetteandratatouille/v6_ui