Fix the removeMount for personal mounts

apps/files_external/lib/config.php

@@ -517,6 +517,7 @@ class OC_Mount_Config {
 		} else {
 			$mountPoint = '/$user/files/'.ltrim($mountPoint, '/');
 		}
+		$mountPoint = \OC\Files\Filesystem::normalizePath($mountPoint);
 		$mountPoints = self::readData($isPersonal ? OCP\User::getUser() : NULL);
 		// Remove mount point
 		unset($mountPoints[$mountType][$applicable][$mountPoint]);

apps/files_external/lib/personalmount.php

@@ -33,6 +33,8 @@ class PersonalMount extends Mount implements MoveableMount {
 	 * @return bool
 	 */
 	public function removeMount() {
-		return \OC_Mount_Config::removeMountPoint($this->mountPoint, \OC_Mount_Config::MOUNT_TYPE_USER, \OCP\User::getUser(), true);
+		$user = \OCP\User::getUser();
+		$relativeMountPoint = substr($this->getMountPoint(), strlen('/' . $user . '/files/'));
+		return \OC_Mount_Config::removeMountPoint($relativeMountPoint, \OC_Mount_Config::MOUNT_TYPE_USER, $user , true);
 	}
 }