Provisioning: Make sure that Perl's Data:Dumper is installed

Data:dumper is critical for release script build.pl. Currently data:dumper
is installed by devtoolset as a dependency for autoconf. But, it seems,
that in earlier version of devtoolset the autoconf wasn't installed by
devtoolset which caused the failure with build.pl.

Change-Id: I487a17ca0eb37c5984eb2f195e1024ed019b80d2
Reviewed-by: Tony Sarajärvi <tony.sarajarvi@qt.io>

coin/provisioning/qtci-linux-RHEL-7.6-x86_64/04-install-packages.sh

@@ -120,6 +120,8 @@ installPackages+=(xz-devel)
 installPackages+=(zlib-devel)
 installPackages+=(libffi-devel)
 installPackages+=(libsqlite3x-devel)
+# Build.pl
+installPackages+=(perl-Data-Dumper)
 
 sudo yum -y install "${installPackages[@]}"