fix cmake, linux only (patch egl)

CMakeLists.txt

@@ -369,11 +369,12 @@ IF(BUILD_PYBULLET)
 
 ENDIF(BUILD_PYBULLET)
 
-OPTION(BUILD_EGL "Build OpenGL/EGL" ON)
-IF(BUILD_EGL)
-    ADD_DEFINITIONS(-DBT_USE_EGL)
-ENDIF(BUILD_EGL)
-
+IF(NOT WIN32 AND NOT APPLE)
+    OPTION(BUILD_EGL "Build OpenGL/EGL" ON)
+    IF(BUILD_EGL)
+        ADD_DEFINITIONS(-DBT_USE_EGL)
+    ENDIF(BUILD_EGL)
+ENDIF()
 
 IF(BUILD_BULLET3)
 	 IF(APPLE)

examples/OpenGLWindow/CMakeLists.txt

@@ -49,9 +49,6 @@ ENDIF()
 
 IF(BUILD_EGL)
     SET(OpenGLWindow_SRCS ${OpenGLWindow_SRCS}  ${BULLET_PHYSICS_SOURCE_DIR}/examples/ThirdPartyLibs/glad/egl.c)
-    IF(APPLE)
-        ADD_DEFINITIONS(-D__APPLE__)
-    ENDIF(APPLE)
 ENDIF(BUILD_EGL)