all: change module to google.golang.org/protobuf

Temporarily remove go.mod, since we can't generate an accurate one until
the corresponding v1 change is submitted.

Change-Id: I1e1ad97f2b455e33f61ffaeb8676289795e47e72
Reviewed-on: https://go-review.googlesource.com/c/protobuf/+/177000
Reviewed-by: Joe Tsai <thebrokentoaster@gmail.com>
diff --git a/encoding/jsonpb/encode.go b/encoding/jsonpb/encode.go
index 256cd74..1d353b7 100644
--- a/encoding/jsonpb/encode.go
+++ b/encoding/jsonpb/encode.go
@@ -9,12 +9,12 @@
 	"fmt"
 	"sort"
 
-	"github.com/golang/protobuf/v2/internal/encoding/json"
-	"github.com/golang/protobuf/v2/internal/errors"
-	"github.com/golang/protobuf/v2/internal/pragma"
-	"github.com/golang/protobuf/v2/proto"
-	pref "github.com/golang/protobuf/v2/reflect/protoreflect"
-	"github.com/golang/protobuf/v2/reflect/protoregistry"
+	"google.golang.org/protobuf/internal/encoding/json"
+	"google.golang.org/protobuf/internal/errors"
+	"google.golang.org/protobuf/internal/pragma"
+	"google.golang.org/protobuf/proto"
+	pref "google.golang.org/protobuf/reflect/protoreflect"
+	"google.golang.org/protobuf/reflect/protoregistry"
 )
 
 // Marshal writes the given proto.Message in JSON format using default options.