Check valid value

[Shougo]

In help,

getqflist()                     *getqflist()*
        Returns a list with all the current quickfix errors.  Each
        list item is a dictionary with these entries:
            bufnr   number of buffer that has the file name, use
                bufname() to get the name
            lnum    line number in the buffer (first line is 1)
            col column number (first column is 1)
            vcol    non-zero: "col" is visual column
                zero: "col" is byte index
            nr  error number
            pattern search pattern used to locate the error
            text    description of the error
            type    type of the error, 'E', '1', etc.
            valid   non-zero: recognized error message

unite-quickfix does not check "valid" value and generate invalid "jump_list" candidates. I think it should check.

[osyo-manga]

Thanks for issues. I added check "valid".

[Shougo]

Thank you!