some cleanup after #194 fix (#196)

Author: Tewr

src/Blazor.FileReader/script/DragnDrop.ts

@@ -154,12 +154,10 @@ function RegisterDropEvents(this: FileReaderComponent, element: HTMLElement, reg
             const filePromise = new Promise<FileList>(async (resolve, reject) => {
                 try {
                     let files = await getFilesAsync(ev.dataTransfer);
-                    if (registerOptions.additive) {
-                        if (existingFilePromise) {
-                            const existing = await existingFilePromise ?? new FileList();
-                            if (existing.length > 0) {
-                                files = new ConcatFileList(existing, files);
-                            }
+                    if (registerOptions.additive && existingFilePromise) {
+                        const existing = await existingFilePromise ?? new FileList();
+                        if (existing.length > 0) {
+                            files = new ConcatFileList(existing, files);
                         }
                     }
                     resolve(files);

src/Blazor.FileReader/wwwroot/FileReaderComponent.js

@@ -219,12 +219,10 @@
                         var _a;
                         try {
                             let files = yield getFilesAsync(ev.dataTransfer);
-                            if (registerOptions.additive) {
-                                if (existingFilePromise) {
-                                    const existing = (_a = yield existingFilePromise) !== null && _a !== void 0 ? _a : new FileList();
-                                    if (existing.length > 0) {
-                                        files = new ConcatFileList_1.ConcatFileList(existing, files);
-                                    }
+                            if (registerOptions.additive && existingFilePromise) {
+                                const existing = (_a = yield existingFilePromise) !== null && _a !== void 0 ? _a : new FileList();
+                                if (existing.length > 0) {
+                                    files = new ConcatFileList_1.ConcatFileList(existing, files);
                                 }
                             }
                             resolve(files);