restore last working MKL libraries

modules/find/FindBLAS.cmake

@@ -843,8 +843,12 @@ if( (NOT BLAS_FOUND_WITH_PKGCONFIG) OR BLAS_GIVEN_BY_USER )
             else()
               set (BLAS_LIBRARIES_SEQ "${${_LIBRARIES}}")
             endif()
+            set(${_LIBRARIES}_COPY "${${_LIBRARIES}}")
           endif()
         endforeach ()
+        if (${_LIBRARIES}_COPY)
+          set(${_LIBRARIES} "${${_LIBRARIES}_COPY}")
+        endif()
         if(NOT BLAS_FIND_QUIETLY)
           if(${_LIBRARIES})
             message(STATUS "Looking for MKL BLAS: found")