Feature/10333 osx nxspe

Mantid help request:
>This works fine on windows, fails on Mac ?linux

>Using version 3.2.1 I get the following error when trying to load an nxspe file

>LoadNXSPE started Error in execution of algorithm LoadNXSPE: Not NeXus or notNXSPE

>It loads fine on my PC version of mantid.

>The file in question is: 
>olympic\babylon5\public\ross\MAP05935_4to1_033.nxspe

>Cheers Ross