BUG: fix name of USE_SYSTEM_QT5 cmake var

3 jobs for !455 with fix-USE_SYSTEM_QT5 in 33 minutes and 20 seconds (queued for 2 seconds)
detached
Status Job ID Name Coverage
  Build
passed #1616
build:ubuntu-llvm

00:23:02

passed #1615
debian-build

00:33:19

passed #1614
native-build

00:24:58