Fix FTBFS

I got this build error with libboost from ubuntu lucid (1.40.0.1):

      CXX    libosd_a-OSDCap.o
    osd/OSDCap.cc: In constructor 'OSDCapParser<Iterator>::OSDCapParser()':
    osd/OSDCap.cc:139: error: 'qi::char_' has not been declared
    osd/OSDCap.cc:140: error: 'qi::int_' has not been declared
    osd/OSDCap.cc:141: error: 'qi::lexeme' has not been declared
    osd/OSDCap.cc:142: error: 'qi::alnum' has not been declared
    osd/OSDCap.cc:143: error: 'qi::_val' has not been declared
    osd/OSDCap.cc:144: error: 'qi::_1' has not been declared
    osd/OSDCap.cc:145: error: 'qi::_2' has not been declared
    osd/OSDCap.cc:146: error: 'qi::_3' has not been declared
    osd/OSDCap.cc:147: error: 'qi::eps' has not been declared
    osd/OSDCap.cc:148: error: 'qi::lit' has not been declared
    osd/OSDCap.cc:151: error: 'lexeme' was not declared in this scope
    osd/OSDCap.cc:151: error: 'char_' was not declared in this scope
    osd/OSDCap.cc:153: error: 'alnum' was not declared in this scope
    ...

The build is successful with libboost from debian squeeze (1.42.0.1) and ubuntu oneiric (1.46.1.1) and precise (1.48.0.2).
This commit is fix the depends.

Signed-off-by: Andras Elso <elso.andras@gmail.com>