[python supervision] Fix paths (#2093). (#2236)

paparazzi-python.sh

@@ -1,3 +0,0 @@
-#!/usr/bin/env /bin/sh
-cd $PAPARAZZI_SRC/sw/supervision/python
-./main.py

src/paparazzi

@@ -13,7 +13,7 @@ let com =
   if Array.length (Sys.argv) > 1 then begin
     Printf.printf "%d\n" (Array.length (Sys.argv));
     if Sys.argv.(1) = "-python" then
-      dirname // "paparazzi-python.sh"
+      dirname // "sw/supervision/python/main.py"
     else
       dirname // "sw/supervision/paparazzicenter"
     end

sw/supervision/python/main.py

@@ -37,6 +37,9 @@ import os
 def main():
     """Main program : creates the main window and starts the main loop."""
 
+    # Set this file's location as working directory
+    os.chdir(os.path.dirname(os.path.abspath(__file__)))
+
     # Set the environment variables (useful for some processes) :
     os.putenv(env.HOME_NAME, env.PAPARAZZI_HOME)
     os.putenv(env.SRC_NAME, env.PAPARAZZI_SRC)