fix typo in entrypoint definition (#1265)

Author: alrex

opentelemetry-sdk/CHANGELOG.md

@@ -4,6 +4,8 @@
 
 - Make `SpanProcessor.on_start` accept parent Context
   ([#1251](https://github.com/open-telemetry/opentelemetry-python/pull/1251))
+- Fix b3 propagator entrypoint
+  ([#1265](https://github.com/open-telemetry/opentelemetry-python/pull/1265))
 
 ## Version 0.14b0
 

opentelemetry-sdk/setup.cfg

@@ -52,7 +52,7 @@ opentelemetry_meter_provider =
 opentelemetry_tracer_provider =
     sdk_tracer_provider = opentelemetry.sdk.trace:TracerProvider
 opentelemetry_propagator =
-    b3 = opentelemetry.sdk.trace.propagation.b3_format.B3Format
+    b3 = opentelemetry.sdk.trace.propagation.b3_format:B3Format
 
 [options.extras_require]
 test =