glsl: fix use of multiple p3d_TextureMatrix[] values

panda/src/glstuff/glShaderContext_src.cxx

@@ -890,6 +890,7 @@ reflect_uniform(int i, char *name_buffer, GLsizei name_buflen) {
 
         // Add it once for each index.
         for (bind._index = 0; bind._index < param_size; ++bind._index) {
+          bind._id._seqno = p + bind._index;
           _shader->_mat_spec.push_back(bind);
         }
         _shader->_mat_deps |= bind._dep[0];