ref_gl: fix enabling multitexturing on GLES

ref/gl/gl2_shim/fragment.glsl.inc

@@ -9,7 +9,7 @@ R"(
 #define in varying
 #define texture texture2D
 #endif
-#if version >= 130
+#if VER >= 130
 precision mediump float;
 #endif
 #if ATTR_TEXCOORD0

ref/gl/gl2_shim/gl2_shim.c

@@ -154,7 +154,7 @@ static GLuint GL2_GenerateShader( gl2wrap_prog_t *prog, GLenum type )
 	int i;
 	GLint status, len;
 	GLuint id, loc;
-	int version = 130;
+	int version = 300;
 
 	shader = shader_buf;
 	//shader[0] = '\n';

ref/gl/gl_opengl.c

@@ -686,9 +686,12 @@ void GL_InitExtensionsGLES( void )
 			GL_CheckExtension( "vertex_buffer_object", vbofuncs, "gl_vertex_buffer_object", extid );
 			break;
 		case GL_ARB_MULTITEXTURE:
-			GL_SetExtension( extid, true ); // required to be supported by wrapper
+			GL_CheckExtension( "multitexture", multitexturefuncs, "gl_arb_multitexture", GL_ARB_MULTITEXTURE );
+			//GL_SetExtension( extid, true ); // required to be supported by wrapper
 
 			pglGetIntegerv( GL_MAX_TEXTURE_UNITS_ARB, &glConfig.max_texture_units );
+			if( glConfig.max_texture_units <= 1 )
+				pglGetIntegerv( GL_MAX_TEXTURE_IMAGE_UNITS_ARB, &glConfig.max_texture_units );
 			if( glConfig.max_texture_units <= 1 )
 			{
 				GL_SetExtension( extid, false );