Memory leak in the `gaussianblur` visualization
I noticed following memory leak when running an example from https://gstreamer.freedesktop.org/documentation/application-development/advanced/pipeline-manipulation.html?gi-language=python#changing-elements-in-a-pipeline
==531204== 4,915,200 bytes in 4 blocks are definitely lost in loss record 2,983 of 2,983
==531204== at 0x483B7F3: malloc (in /usr/lib/x86_64-linux-gnu/valgrind/vgpreload_memcheck-amd64-linux.so)
==531204== by 0x4A81E98: g_malloc (in /usr/lib/x86_64-linux-gnu/libglib-2.0.so.0.6400.6)
==531204== by 0x4855725: gst_gaussianblur_set_info (gstgaussblur.c:173)
==531204== by 0x6508FCE: ??? (in /usr/lib/x86_64-linux-gnu/libgstvideo-1.0.so.0.1602.0)
==531204== by 0x648B1EB: ??? (in /usr/lib/x86_64-linux-gnu/libgstbase-1.0.so.0.1602.0)
==531204== by 0x648CF29: ??? (in /usr/lib/x86_64-linux-gnu/libgstbase-1.0.so.0.1602.0)
==531204== by 0x48FEBB3: ??? (in /usr/lib/x86_64-linux-gnu/libgstreamer-1.0.so.0.1602.0)
==531204== by 0x48FF163: ??? (in /usr/lib/x86_64-linux-gnu/libgstreamer-1.0.so.0.1602.0)
==531204== by 0x48FF5D9: ??? (in /usr/lib/x86_64-linux-gnu/libgstreamer-1.0.so.0.1602.0)
==531204== by 0x48FD01F: ??? (in /usr/lib/x86_64-linux-gnu/libgstreamer-1.0.so.0.1602.0)
==531204== by 0x4907D70: gst_pad_push_event (in /usr/lib/x86_64-linux-gnu/libgstreamer-1.0.so.0.1602.0)
==531204== by 0x648BAA7: ??? (in /usr/lib/x86_64-linux-gnu/libgstbase-1.0.so.0.1602.0)