fix gameOfLife

[psychocoderHPC]

The game of life example has a runtime issue that the mapping description verification
to check the number of supercells is always twrowing an error. The reason it that the
not existing default constructor is MappingDescription is used.
Please do not ask me why the code before is compiling. The class MappingDescription has no default constructor but is a not initialized member of the class Evolution<> which means by definition the default constructor should be called. Due to the fact that there is a user defined constructor there should be no default constructor available.

Error message:

./gameOfLife -d  1 1  -g 128 128 -p 1 1 -r 23/3 -s 100
newborn if=3 stay alive if=23 mask=4108
terminate called after throwing an instance of 'std::runtime_error'
  what():  expression (( guardingSuperCells[ d ] == 0 && gridSuperCells[ d ] >= 1) || gridSuperCells[ d ] >= 2 * guardingSuperCells[ d ] + 1) failed in file (/include/pmacc/mappings/kernel/MappingDescription.hpp:82) : 
Aborted

• create the object for mapping description inside the init method of Evolution
• change interface of Evolution<...>::init()
• remove the default constructor for MappingDescription (it make no sense to allow a mapping with zero cells)

[sbastrakov]

@psychocoderHPC the constructor of MappingDescription has default values for both parameters, so it is also a default constructor and therefore previously the code has compiled successfully (but maybe it would be better if that did not compile, see my next comment).

[sbastrakov]

I have nothing against these changes. However, doesn't the fact these are required mean that the default constructor of MappingDescription (default parameter values) is actually harmful as it initializes in an invalid state?

[psychocoderHPC]

@sbastrakov Thanks I missed the fact that there is a default for all parameter. I fully agree that it should not MappingDescription should not be default constructable, this bug shows why.

I will fix it by changing the interface of MappingDescription

[psychocoderHPC]

I removed the default constructor for MappingDescription