[NTG-context] Problem including svg files with Inkscape 1.0~rc1-4

Hi, The last release candidat of Inkscape (1.0~rc1-4 on my Debian sid) doesn't provide the `--export-pdf=` option anymore. So context can not convert svg files into the corresponding `m_k_i_v_*` pdf. It seems that the `--export-filename=` option does the job. Thank in advance. -- Romain Diss