Fixed: Link to X11 under Linux

--HG--
branch : develop

code/nel/src/3d/driver/opengl/CMakeLists.txt

@@ -1,16 +1,18 @@
-FIND_PACKAGE(OpenGL REQUIRED)
-
 IF(NOT WIN32)
   IF(APPLE)
     FIND_LIBRARY(CARBON NAMES Carbon)
     FIND_LIBRARY(COCOA NAMES Cocoa)
+    FIND_PACKAGE(OpenGL REQUIRED)
   ELSE()
     SET(OLD_CMAKE_FIND_LIBRARY_SUFFIXES ${CMAKE_FIND_LIBRARY_SUFFIXES})
     SET(CMAKE_FIND_LIBRARY_SUFFIXES .so)
     FIND_PACKAGE(X11)
     FIND_PACKAGE(XF86VidMode)
+    FIND_PACKAGE(OpenGL REQUIRED)
     SET(CMAKE_FIND_LIBRARY_SUFFIXES ${OLD_CMAKE_FIND_LIBRARY_SUFFIXES})
   ENDIF()
+ELSE()
+  FIND_PACKAGE(OpenGL REQUIRED)
 ENDIF()
 
 FILE(GLOB SRC *.cpp *.h *.def *.rc)