Fix knudsen pump stuy by removing too large mesh

examples/knudsen_pump/study/create_mesh.sh

 #!/bin/bash
-for p in $(seq 4 9)
+for p in $(seq 4 8)
 do
   geoToH5 ../knudsen_pump.geo knudsen_pump"$p".h5 "-setnumber p $p"
 done

examples/knudsen_pump/study/input.yml

@@ -12,7 +12,6 @@ meshes:
   - knudsen_pump6.h5
   - knudsen_pump7.h5
   - knudsen_pump8.h5
-  - knudsen_pump9.h5
 
 # Numerical Parameters
 # ====================