remove obsolete code in variables.py
remove obsolete code in variables.py

vlukes/sfepy,lokik/sfepy,olivierverdier/sfepy,vlukes/sfepy,BubuLK/sfepy,sfepy/sfepy,rc/sfepy,RexFuzzle/sfepy,sfepy/sfepy,lokik/sfepy,RexFuzzle/sfepy,BubuLK/sfepy,olivierverdier/sfepy,rc/sfepy,vlukes/sfepy,olivierverdier/sfepy,RexFuzzle/sfepy,RexFuzzle/sfepy,sfepy/sfepy,lokik/sfepy,rc/sfepy,BubuLK/sfepy,lokik/sfepy