Fix re-export of TEXT_FORMAT to not require protobuf (#416)

A minor change, but previously the root-level re-export of
TEXT_FORMAT would require cfg(feature = "protobuf"), despite
the text export format not requiring protobufs.  Since this is
the only location where TEXT_FORMAT is made public, it should
be exported regardless of protobuf feature availability.

Signed-off-by: Jeremy Rodi <me@telios.dev>

src/lib.rs

@@ -211,7 +211,8 @@ pub use self::encoder::Encoder;
 pub use self::encoder::ProtobufEncoder;
 pub use self::encoder::TextEncoder;
 #[cfg(feature = "protobuf")]
-pub use self::encoder::{PROTOBUF_FORMAT, TEXT_FORMAT};
+pub use self::encoder::PROTOBUF_FORMAT;
+pub use self::encoder::TEXT_FORMAT;
 pub use self::errors::{Error, Result};
 pub use self::gauge::{Gauge, GaugeVec, IntGauge, IntGaugeVec};
 pub use self::histogram::DEFAULT_BUCKETS;