set active texture in GL, not Font module

src/Font.cc

@@ -157,7 +157,6 @@ bool Glyph::load(FT_Face face, FT_ULong char_code)
                width);
     }
 
-    glActiveTexture(GL_TEXTURE0);
     m_texture = new GLTexture();
     m_texture->create(width, height);
     glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_CLAMP_TO_EDGE);

src/GL.cc

@@ -107,6 +107,7 @@ void GL_Load()
     }
 
     glEnable(GL_SCISSOR_TEST);
+    glActiveTexture(GL_TEXTURE0);
 
     loaded = true;
 }