Repair fit galaxi example

Examples/fit61_Galaxi/fit_galaxi_data.py

@@ -4,8 +4,9 @@ Fitting experimental data: spherical nanoparticles with size distribution
 in 3 layers system (experiment at GALAXI).
 """
 import bornagain as ba
-from bornagain import nm as nm
+from bornagain import nm
 from sample_builder import SampleBuilder
+from matplotlib import pyplot as plt
 
 wavelength = 1.34*ba.angstrom
 alpha_i = 0.463*ba.deg
@@ -77,3 +78,4 @@ def run_fitting():
 
 if __name__ == '__main__':
     run_fitting()
+    plt.show()

Examples/fit61_Galaxi/sample_builder.py

@@ -4,6 +4,7 @@
 Vacuum layer is populated with spheres with size distribution.
 """
 import bornagain as ba
+from bornagain import nm
 
 
 class SampleBuilder: