THRIFT-500. Remove unnecessary "ACLOCAL_AMFLAGS" line from lib/cpp/Makefile.am

git-svn-id: https://svn.apache.org/repos/asf/incubator/thrift/trunk@991242 13f79535-47bb-0310-9956-ffa450edef68
diff --git a/lib/cpp/Makefile.am b/lib/cpp/Makefile.am
index bf2fe26..e83b182 100644
--- a/lib/cpp/Makefile.am
+++ b/lib/cpp/Makefile.am
@@ -17,8 +17,6 @@
 # under the License.
 #
 
-ACLOCAL_AMFLAGS = -I ./aclocal
-
 pkgconfigdir = $(libdir)/pkgconfig
 
 lib_LTLIBRARIES = libthrift.la