fix make_l2_projection_data() for parameter variables
fix make_l2_projection_data() for parameter variables

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