Can't install rmagick on debian 7.6 (package conflicts)

I am trying to install redmine 2.5.4 on Debian 7.6 (Wheezy). And I am facing the problem why I am trying to install the rmagick gem.

I try apt-get install libmagickwand-dev libmysqlclient-dev

and apt-get install libmagick++-dev

but I cannot install. Indeed, the conflict emerged after:

maxime@ns504687:/opt/redmine$ sudo aptitude why-not libmagick++-dev
i   imagemagick                         Suggests  html2ps
p   html2ps                             Depends   perlmagick
p   graphicsmagick-libmagick-dev-compat Provides  perlmagick
p   graphicsmagick-libmagick-dev-compat Conflicts libmagick++-dev

      

        
        
        
      

    

Here is the result apt-get install libmagickwand-dev libmysqlclient-dev

maxime@ns504687:/opt/redmine$ sudo apt-get install libmagickwand-dev libmysqlclient-dev
Reading package lists... Done
Building dependency tree
Reading state information... Done
libmysqlclient-dev is already the newest version.
libmysqlclient-dev set to manually installed.
Some packages could not be installed. This may mean that you have
requested an impossible situation or if you are using the unstable
distribution that some required packages have not yet been created
or been moved out of Incoming.
The following information may help to resolve the situation:

The following packages have unmet dependencies:
 libmagickwand-dev : Depends: libmagickcore-dev (= 8:6.7.7.10-5+deb7u3) but it is not going to be installed
E: Unable to correct problems, you have held broken packages.

      

        
        
        
      

    

And here is the result for apt-get install libmagick++-dev

:

maxime@ns504687:/opt/redmine$ sudo apt-get install libmagick++-dev
Reading package lists... Done
Building dependency tree
Reading state information... Done
Some packages could not be installed. This may mean that you have
requested an impossible situation or if you are using the unstable
distribution that some required packages have not yet been created
or been moved out of Incoming.
The following information may help to resolve the situation:

The following packages have unmet dependencies:
 libmagick++-dev : Depends: libmagickcore-dev (= 8:6.7.7.10-5+deb7u3) but it is not going to be installed
                   Depends: libmagickwand-dev (= 8:6.7.7.10-5+deb7u3) but it is not going to be installed
E: Unable to correct problems, you have held broken packages.

      

        
        
        
      

    

I tried to find many solutions on the internet but none worked.

Can you help me?