package/python-pyroute2: add missing python3 ssl dependency

Buildroot commit [1] "package/python-pyroute2: bump to version 0.9.4"
added the python3 ssl runtime dependency while updating the package
in the "next" branch. It incorrectly suggested the dependency was
introduced in version 0.9.4.

This dependency was in fact introduced in upstream commit [2],
first time included in pyroute2 0.8.1, which is the current version
in the Buildroot release stabilization branch. It is worth mentioning
that this package was updated to that version in Buildroot commit [3].

Running the command on target:

    python3 -c 'import pyroute2'

Fails at runtime with error:

    ModuleNotFoundError: No module named '_ssl'

This commit fixes the issue by adding this missing dependency,
the same was it was done in commit [1].

[1] 786557d859
[2] e87c14581b
[3] 816641bbe1

Signed-off-by: Yacin Belmihoub-Martel <yacin.belmihoub-martel@silabs.com>
[Julien:
 - reword commit log
 - add the "runtime" comment
]
Signed-off-by: Julien Olivain <ju.o@free.fr>

package/python-pyroute2/Config.in

@@ -1,6 +1,7 @@
 config BR2_PACKAGE_PYTHON_PYROUTE2
 	bool "python-pyroute2"
 	select BR2_PACKAGE_PYTHON3_SQLITE
+	select BR2_PACKAGE_PYTHON3_SSL # runtime
 	help
 	  Python netlink library - Linux network / netns / wireless /
 	  ipset configuration.