apply suggestions

Co-authored-by: Sebastian Blank <blank@data-factory.net>

Author: kingjia90

resources/functionMap.php

@@ -5016,9 +5016,9 @@
 'Imagick::waveImage' => ['bool', 'amplitude'=>'float', 'length'=>'float'],
 'Imagick::whiteThresholdImage' => ['bool', 'threshold'=>'mixed'],
 'Imagick::writeImage' => ['bool', 'filename='=>'string'],
-'Imagick::writeImageFile' => ['bool', 'filehandle'=>'resource', 'format'=>'string'],
+'Imagick::writeImageFile' => ['bool', 'filehandle'=>'resource', 'format'=>'?string'],
 'Imagick::writeImages' => ['bool', 'filename'=>'string', 'adjoin'=>'bool'],
-'Imagick::writeImagesFile' => ['bool', 'filehandle'=>'resource'],
+'Imagick::writeImagesFile' => ['bool', 'filehandle'=>'resource', 'format'=>'?string'],
 'ImagickDraw::__construct' => ['void'],
 'ImagickDraw::affine' => ['bool', 'affine'=>'array'],
 'ImagickDraw::annotation' => ['bool', 'x'=>'float', 'y'=>'float', 'text'=>'string'],