Folded subject header using ISO-2022-JP doesn't get decoded properly in Safari

[larabr]

The test case related to Thunderbird's Bug 1374149 fails in WebKit/Safari.

Since this is an edge case, and it seems to be a WebKit issue (as Chrome and Firefox process the string correctly), we won't attempt to patch this for now, unless we receive reports of users impacted by the problem.

Affected test case:

jsmimeparser/test/test_header_parser.js

Lines 1130 to 1136 in 53491be

	// Test for bug 1374149 with ISO-2022-JP where we shouldn't stream
	// if the first token ends in ESC(B.
	// GyRCJCIbKEI= is the base64 encoding of ESC$B$"ESC(B.
	[
	"=?ISO-2022-JP?B?GyRCJCIbKEI=?==?ISO-2022-JP?B?GyRCJCIbKEI=?=",
	isWebKit() ? "あ\ufffdあ" : "ああ" // see https://github.com/ProtonMail/jsmimeparser/issues/1
	],