Slightly change again glext.h conditional include
Slightly change again glext.h conditional include

WNT is always defined when compiling with Mingw.

BenoitPerrot/oce,Tridify/oce,mathstuf/oce,heartvalve/oce,BenoitPerrot/oce,mathstuf/oce,BenoitPerrot/oce,EvgeneOskin/oce,mathstuf/oce,finetjul/oce,Tech-XCorp/oce,Tridify/oce,Tech-XCorp/oce,heartvalve/oce,mathstuf/oce,BenoitPerrot/oce,BenoitPerrot/oce,EvgeneOskin/oce,finetjul/oce,mathstuf/oce,finetjul/oce,tpaviot/oce,Tech-XCorp/oce,tpaviot/oce,finetjul/oce,EvgeneOskin/oce,EvgeneOskin/oce,heartvalve/oce,heartvalve/oce,tpaviot/oce,Tech-XCorp/oce,EvgeneOskin/oce,Tech-XCorp/oce,Tridify/oce,finetjul/oce,tpaviot/oce,tpaviot/oce,Tridify/oce,Tridify/oce,heartvalve/oce