Improved code based on CppCheck results

None of this should change the engine's behavior, but the code is better
this way.


Former-commit-id: 0127769848fc1f7fc8006ee607985cfc0ead2965

src/Nazara/Renderer/OpenGL.cpp

@@ -781,7 +781,7 @@ bool NzOpenGL::Initialize()
 	major = version[0] - '0';
 	minor = version[2] - '0';
 
-	if (major <= 0 || major > 9)
+	if (major == 0 || major > 9)
 	{
 		NazaraError("Unable to retrieve OpenGL major version");
 		return false;