erp5: set version of more-itertools

more-itertools is a hidden dependency, not managed by buildout.
It has dropped support for python2 after version 5.0.0

stack/erp5/buildout.cfg

@@ -455,6 +455,7 @@ eggs = ${neoppod:eggs}
   ${scikit-learn:egg}
   ${scikit-image:egg}
   sympy
+  more-itertools
   ${h5py:egg}
   openpyxl
   ${statsmodels:egg}
@@ -785,6 +786,7 @@ zope.app.form = 4.0.2
 
 Cython = 0.26.1
 et-xmlfile = 1.0.1
+more-itertools = 5.0.0
 h5py = 2.7.1
 mpmath = 0.19
 openpyxl = 2.4.8