Downgrade glsl required version to 3.3 supported by OGL 3.3.

It's for old hardware compatiblity since OGL 4.x features are not used.

Author: deltaoscarmike

src/libprojectM/Renderer/ShaderEngine.cpp

@@ -17,7 +17,7 @@
 #ifdef USE_GLES
     #define GLSL_VERSION "300 es"
 #else
-    #define GLSL_VERSION "410"
+    #define GLSL_VERSION "330"
 #endif