Examples: SDL: Fixed minor warning.

examples/sdl_opengl3_example/imgui_impl_sdl_gl3.cpp

@@ -39,7 +39,7 @@
 #include <GL/gl3w.h>    // This example is using gl3w to access OpenGL functions (because it is small). You may use glew/glad/glLoadGen/etc. whatever already works for you.
 
 // Data
-static Uint64       g_Time = 0.0f;
+static Uint64       g_Time = 0;
 static bool         g_MousePressed[3] = { false, false, false };
 static GLuint       g_FontTexture = 0;
 static int          g_ShaderHandle = 0, g_VertHandle = 0, g_FragHandle = 0;