Enable ZipStreamer compression

[PVince81]

In https://github.com/nextcloud/user_migration/blob/main/lib/ExportDestination.php#L50 set to:

				'compress' => COMPR::DEFLATE,
				'level' => COMPR::MAXIMUM,

for me locally this leads to this error: https://github.com/DeepDiver1975/PHPZipStreamer/blob/master/src/ZipStreamer.php#L310

even after installing sudo pecl install pecl_http and enabling the "raphf" module, the error still appears.

• needs further research
• make it conditional
• document what is needed to enable compression