Updated package name in ovf_lut.proto

Proto-package name inf `ovf_lut.proto` was `OpenVectorFormat`, now is `open_vector_format`, thus in line with `open_vector_format.proto` and the protobuf style guide.

Author: ax-meyer

ovf_lut.proto

@@ -21,7 +21,7 @@
 // SOFTWARE.
 
 syntax = "proto3";
-package OpenVectorFormat;
+package open_vector_format;
 option go_package = "github.com/digital-production-aachen/openvectorformat/proto";
 
 // positions are 64bit values in bytes