fix(share): Send empty expireDate when not expireDate set

When creating a new share, if the user unchecks "Set expiry date"
no `expireDate` is sent to the server.

However, the server then assumes the default configured, hence better
to send an empty value.

Signed-off-by: fenn-cs <fenn25.fn@gmail.com>

apps/files_sharing/src/views/SharingDetailsTab.vue

@@ -868,9 +868,7 @@ export default {
 					fileInfo: this.fileInfo,
 				}
 
-				if (this.hasExpirationDate) {
-					incomingShare.expireDate = this.share.expireDate
-				}
+				incomingShare.expireDate = this.hasExpirationDate ? this.share.expireDate : ''
 
 				if (this.isPasswordProtected) {
 					incomingShare.password = this.share.password
@@ -912,9 +910,9 @@ export default {
 					shareWith: share.shareWith,
 					permissions: share.permissions,
 					attributes: JSON.stringify(fileInfo.shareAttributes),
+					expireDate: share.expireDate,
 					...(share.note ? { note: share.note } : {}),
 					...(share.password ? { password: share.password } : {}),
-					...(share.expireDate ? { expireDate: share.expireDate } : {}),
 				})
 				return resultingShare
 			} catch (error) {