The curl tool project files for VC7 to VC12 would override the default
setting with the output filename being the same as the linker PDB file.
As such the compiler file would be overwritten with the linker file
for all debug builds.
To avoid this overwrite and for consistency with the libcurl project
files, removed the setting to force the default filename to be used.
Carrying on from commit 11025613b9 added VC7 project files which are
capable of supporting side-by-side compilation, as well as support for
some of the third-party libraries curl uses.
