disable import button if file isn't valid

src/views/FeatureType/FeatureTypeDetail.vue

@@ -765,6 +765,9 @@ export default {
         if (jsonValidity) {
           this.geojsonFileToImport = files[0]; // TODO: Remove this value from state as it is stored (first attempt didn't work)
           this.SET_FILE_TO_IMPORT(this.geojsonFileToImport);
+        } else {
+          // Clear any previously selected geojson file to disable import button
+          this.geojsonFileToImport = geojsonFileToImport;
         }
 
         // Stop the loading process
@@ -826,6 +829,9 @@ export default {
         if (csvValidity) {
           this.csvFileToImport = files[0]; // TODO: Remove this value from state as it is stored (first attempt didn't work)
           this.SET_FILE_TO_IMPORT(this.csvFileToImport);
+        } else {
+          // Clear any previously selected geojson file to disable import button
+          this.csvFileToImport = csvFileToImport;
         }
 
         // Stop the loading process