CppTools: Remove workaround for quotes in defines

...since by now we get the defines in the correct format from
QMakeProject.

See the change this one depends on.

Tested with:

    Qbs:   cpp.defines: [ 'PATH1="/some/path"', "PATH2=\"/some/path\"" ]
    QMake: DEFINES += PATH1=\\\"/some/path\\\" "PATH2=\\\"/some/path\\\""
    CMake: add_definitions(-DPATH1="/some/path" "-DPATH2=\"/some/path\"")

All these lines translate to

    #define PATH1 "/some/path"
    #define PATH2 "/some/path"

for the code model.

Change-Id: Ifc3d3acff3abab6897ccbd0c5fafd5c415dfb53c
Reviewed-by: Erik Verbruggen <erik.verbruggen@theqtcompany.com>

src/plugins/cpptools/cppprojects.cpp

@@ -556,8 +556,6 @@ QStringList CompilerOptionsBuilder::createDefineOptions(const QByteArray &define
         QString arg = option + QLatin1String(str.left(hasValue ? spaceIdx : str.size()) + '=');
         if (hasValue)
             arg += QLatin1String(str.mid(spaceIdx + 1));
-        arg = arg.replace(QLatin1String("\\\""), QLatin1String("\""));
-        arg = arg.replace(QLatin1String("\""), QLatin1String(""));
         if (!result.contains(arg))
             result.append(arg);
     }