[REG 5.6.0->5.6.1] Building example "TextureProvider" fails due to missing opengl32.lib

When building Qt 5.6.1 with examples, building the example "TextureProvider" will fail due to missing opengl32.lib. In 5.6.0 build succeeded with the same configuration parameters. Manually adding opengl32.lib to the build fixes this error.

Steps to reproduce:

• Build Qt 5.6.1, including examples, with given configuration
• EXPECTED: Build succeeds
• ACTUAL: Building of example "TextureProvider" fails

Used configuration:
..\qt-everywhere-enterprise-src-5.6.1\configure -commercial -debug-and-release -platform win32-msvc2015 -skip qtwebengine -skip qtsensors -skip qtconnectivity -developer-build -shared -force-debug-info -opengl dynamic -nomake tests