Fix reloading of plugins

Unloading and reloading a plugin didn't work correctly,
because we didn't reset instance to 0 on unload.

Task-number: QTBUG-26098
Change-Id: Ic3e4497f359b1ca455be949dce9cafa9d67d8039
Reviewed-by: Thiago Macieira <thiago.macieira@intel.com>

1 files changed, 1 insertions, 0 deletions

diff --git a/src/corelib/plugin/qlibrary.cpp b/src/corelib/plugin/qlibrary.cpp
index 3815082989..2217140cbf 100644
--- a/src/corelib/plugin/qlibrary.cpp
+++ b/src/corelib/plugin/qlibrary.cpp
@@ -429,6 +429,7 @@ bool QLibraryPrivate::unload()
                     libraryRefCount.deref();
             }
             pHnd = 0;
+            instance = 0;
         }
     }