Incorrect values for some NPI constants

[scop]

The numeric values for NPI_(DATA|TELEX|LAND_MOBILE|ERMES|INTERNET|WAP) in SMPPConstant.java are incorrect, the correct ones would be:

    public static final byte NPI_DATA = 0x03;
    public static final byte NPI_TELEX = 0x04;
    public static final byte NPI_LAND_MOBILE = 0x06;
    public static final byte NPI_ERMES = 0x0a;
    public static final byte NPI_INTERNET = 0x0e;
    public static final byte NPI_WAP = 0x12;

[scop]

See pull request #26