Defining time_t for Python

Fixes: lp:1732738
* https://bugs.launchpad.net/kicad/+bug/1732738

common/swig/kicad.i

@@ -112,6 +112,8 @@ principle should be easily implemented by adapting the current STL containers.
 %include marker_base.h
 %include eda_text.h
 
+// Cast time_t to known type for Python
+typedef long time_t;
 
 // std template mappings
 %template(intVector) std::vector<int>;