Remove old protobuf tarballs.

Bug:27777866
Change-Id: I02b570f4ebd66913396720a0ef43285f31a509c3
diff --git a/protobuf-cpp-3.0.0-alpha-2.tar.gz b/protobuf-cpp-3.0.0-alpha-2.tar.gz
deleted file mode 100644
index 0d24af2..0000000
--- a/protobuf-cpp-3.0.0-alpha-2.tar.gz
+++ /dev/null
Binary files differ
diff --git a/protobuf-cpp-3.0.0-alpha-3.tar.gz b/protobuf-cpp-3.0.0-alpha-3.tar.gz
deleted file mode 100644
index 028cc28..0000000
--- a/protobuf-cpp-3.0.0-alpha-3.tar.gz
+++ /dev/null
Binary files differ
diff --git a/protobuf-cpp-3.0.0-beta-1.tar.gz b/protobuf-cpp-3.0.0-beta-1.tar.gz
deleted file mode 100644
index 3221497..0000000
--- a/protobuf-cpp-3.0.0-beta-1.tar.gz
+++ /dev/null
Binary files differ