spawner.py: Fix python logging on deprecation warning

[fmauch]

This was an error introduced in abd5d6e

[fmauch]

Fixed the related commit hash in the commit comment.

[codecov-commenter]

Codecov Report

Merging #787 (6477052) into master (925f5f3) will decrease coverage by 1.70%.
The diff coverage is 37.26%.

@@            Coverage Diff             @@
##           master     #787      +/-   ##
==========================================
- Coverage   34.61%   32.91%   -1.71%     
==========================================
  Files          52       90      +38     
  Lines        2981     8497    +5516     
  Branches     1855     5658    +3803     
==========================================
+ Hits         1032     2797    +1765     
- Misses        310      674     +364     
- Partials     1639     5026    +3387     

Flag	Coverage Δ
unittests	32.91% <37.26%> (-1.71%)	⬇️

Flags with carried forward coverage won't be shown. Click here to find out more.

Impacted Files	Coverage Δ
controller_manager/src/realtime.cpp	0.00% <0.00%> (ø)
controller_manager/src/ros2_control_node.cpp	0.00% <0.00%> (ø)
..._interface/include/hardware_interface/actuator.hpp	100.00% <ø> (ø)
...re_interface/include/hardware_interface/sensor.hpp	100.00% <ø> (ø)
...re_interface/include/hardware_interface/system.hpp	100.00% <ø> (ø)
hardware_interface/src/resource_manager.cpp	50.09% <ø> (-3.53%)	⬇️
hardware_interface/src/sensor.cpp	50.52% <ø> (ø)
hardware_interface/src/system.cpp	55.45% <ø> (ø)
...rface/test/mock_components/test_generic_system.cpp	8.62% <ø> (ø)
...dware_interface/test/test_component_interfaces.cpp	32.44% <ø> (+4.25%)	⬆️
... and 106 more