Fix Snapmaker Luban support (#123)

* Fix Snapmaker Luban support

In the latest version of Luban the formatting has changed slightly. This adds Luban support back. This will only work with newly sliced gcodes.
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Co-authored-by: jneilliii <jneilliii+github@gmail.com>

octoprint_prusaslicerthumbnails/__init__.py

@@ -70,7 +70,7 @@ def _extract_thumbnail(self, gcode_filename, thumbnail_filename):
 		regex = r"(?:^; thumbnail(?:_JPG)* begin \d+[x ]\d+ \d+)(?:\n|\r\n?)((?:.+(?:\n|\r\n?))+?)(?:^; thumbnail(?:_JPG)* end)"
 		regex_mks = re.compile('(?:;(?:simage|;gimage):).*?M10086 ;[\r\n]', re.DOTALL)
 		regex_weedo = re.compile('W221[\r\n](.*)[\r\n]W222', re.DOTALL)
-		regex_luban = re.compile(';thumbnail: data:image/png;base64,(.*)[\r\n]', re.DOTALL)
+		regex_luban = re.compile(';[Tt]humbnail: ?data:image/png;base64,(.*)[\r\n]', re.DOTALL)
 		regex_qidi = re.compile('M4010.*\'(.*)\'', re.DOTALL)
 		regex_creality = r"(?:^; jpg begin .*)(?:\n|\r\n?)((?:.+(?:\n|\r\n?))+?)(?:^; jpg end)"
 		regex_buddy = r"(?:^; thumbnail(?:_QOI)* begin \d+[x ]\d+ \d+)(?:\n|\r\n?)((?:.+(?:\n|\r\n?))+?)(?:^; thumbnail(?:_QOI)* end)"