package/python-pyzmq: drop python2 dependency for comment

The package was updated to support python3 in commit 4a8bedc51d9
(python-pyzmq: enable PyZMQ for Python 3), but the comment dependency was
missed.

Signed-off-by: Peter Korsgaard <peter@korsgaard.com>
Signed-off-by: Yann E. MORIN <yann.morin.1998@free.fr>

package/python-pyzmq/Config.in

@@ -9,5 +9,4 @@ config BR2_PACKAGE_PYTHON_PYZMQ
 	  http://zeromq.org/bindings:python
 
 comment "python-pyzmq needs a toolchain w/ C++, threads"
-	depends on BR2_PACKAGE_PYTHON
 	depends on !(BR2_INSTALL_LIBSTDCPP && BR2_TOOLCHAIN_HAS_THREADS)