Add .lib and .exp files to clean targets only for libraries

There is no point in adding those to applications.

Change-Id: Ic8d3009b5099c266f56b5bdaa831d0816510bc3b
Reviewed-by: Oliver Wolff <oliver.wolff@qt.io>

qmake/generators/win32/msvc_nmake.cpp

@@ -254,7 +254,7 @@ void NmakeMakefileGenerator::init()
 
     ProString tgt = project->first("DESTDIR")
                     + project->first("TARGET") + project->first("TARGET_VERSION_EXT");
-    if(project->isActiveConfig("shared")) {
+    if (project->first("TEMPLATE") == "lib" && project->isActiveConfig("shared")) {
         project->values("QMAKE_CLEAN").append(tgt + ".exp");
         project->values("QMAKE_DISTCLEAN").append(tgt + ".lib");
     }