Fix Musker's law

Due to inconsistencies between the original paper by Musker and Malaspina's formulation, we used the wrong logarithm in the implementation of Musker's law (decimal instead of natural logarithm). This MR introduces the natural logarithm to fit Malaspina's formulation.

src/lbmpy/boundaries/wall_function_models.py

@@ -157,7 +157,7 @@ class MuskerLaw(ImplicitWallFunctionModel):
         def law(u_p, y_p):
             arctan = sp.Float(5.424) * sp.atan(sp.Float(0.119760479041916168) * y_p - sp.Float(0.488023952095808383))
             logarithm = (sp.Float(0.434) * sp.log((y_p + sp.Float(10.6)) ** sp.Float(9.6)
-                                                  / (y_p ** 2 - sp.Float(8.15) * y_p + sp.Float(86)) ** 2, 10))
+                                                  / (y_p ** 2 - sp.Float(8.15) * y_p + sp.Float(86)) ** 2))
             return (arctan + logarithm - sp.Float(3.50727901936264842)) - u_p
 
         u_plus = velocity_symbol / self.u_tau[0]