[BUGFIX] Correctly check decoded content

On publishing a new extension version, the content of each
file is checked against the calculated MD5 checksum. If the
file content is however an empty string, this check previously
failed. Therefore, the `$decodedContent` is now strictly
checked for `false`.
10 jobs for 504-error-md5-does-not-match-for-file-classes-on-version-upload in 6 minutes and 43 seconds (queued for 3 seconds)
Status Job ID Name Coverage
  Maintenance
manual #29899
allowed to fail manual
Get dump for local environment
 
  Test
passed #29902
test:composer

00:01:46

passed #29904
test:mutation

00:03:41

passed #29901
test:php

00:00:18

passed #29900
test:typoscript

00:00:16

passed #29903
test:unit

00:03:21

13.91%
 
  Build
passed #29905
build

00:00:39

 
  Layout
passed #29906
layout

00:01:27

 
  Badges
passed #29907
Create Badge

00:00:48

passed #29908
mutation:badge

00:00:51