Removed whitespace if no role is provided

[SimonPaul02]

If you had no role -> {} in your cventry, there was a gap before. Now, I removed it and it looks natural.

Testing: Create a cventry without a role, there should not be any gaps:

The code for the entry:

\cventry
    {}  % empty
    {B10S (B1t 0n the Security, Underground hacker team)} % Organization/group
    {S.Korea} % Location
    {Nov. 2011 - PRESENT} % Date(s)
    {
      \begin{cvitems} % Description(s) of experience/contributions/knowledge
        \item {Gained expertise in penetration testing areas, especially targeted on web application and software.}
        \item {Participated on a lot of hacking competition and won a good award.}
        \item {Held several hacking competitions non-profit, just for fun.}
      \end{cvitems}
    }

[fulcus]

For some reason it doesn't work if there's only one item...