fix: crop save dropped blue channel brightness/contrast offset (v1.4.2)

m[13] (blue alpha coefficient, always 0) was read as the blue offset instead of
m[14], so saved JPEGs lost the blue brightness/contrast offset and came out with a
color cast. Saturation/rotate were unaffected (no offsets).

Also: version 1.4.2, CHANGELOG entry, dist/ ships imajviewer_1.4.2_amd64.deb
(replaces 1.4.1).

.gitignore

@@ -49,7 +49,7 @@ app.*.map.json
 *.deb
 *.tar.gz
 *.exe
-!dist/imajviewer_1.4.1_amd64.deb
+!dist/imajviewer_1.4.2_amd64.deb
 !dist/imajviewer_setup_1.1.0.exe
 deb/usr/lib/imajviewer/
 release/