Added a missing header in Makefile

Summary: Pull Request resolved: https://github.com/facebook/folly/pull/910

Reviewed By: simpkins

Differential Revision: D9300288

Pulled By: yfeldblum

fbshipit-source-id: 5724bcc2e9c6602a0e99c436b62893926281e673

folly/Makefile.am

@@ -292,6 +292,7 @@ nobase_follyinclude_HEADERS = \
 	io/async/ssl/OpenSSLUtils.h \
 	io/async/ssl/SSLErrors.h \
 	io/async/ssl/TLSDefinitions.h \
+	io/async/PasswordInFile.h \
 	io/async/Request.h \
 	io/async/SSLContext.h \
 	io/async/SSLOptions.h \
@@ -603,6 +604,7 @@ libfolly_la_SOURCES = \
 	io/async/EventBaseManager.cpp \
 	io/async/EventBaseThread.cpp \
 	io/async/EventHandler.cpp \
+	io/async/PasswordInFile.cpp \
 	io/async/Request.cpp \
 	io/async/SSLContext.cpp \
 	io/async/SSLOptions.cpp \