write_riemann: only compile .proto files when enabled

If the write_riemann plugin is not enabled there's no
need to compile the protobuf files.

diff --git a/src/Makefile.am b/src/Makefile.am
index 8674658..52210da 100644 (file)
--- a/src/Makefile.am
+++ b/src/Makefile.am
@@ -1378,7 +1378,7 @@ endif
 
 # Protocol buffer for the "write_riemann" plugin.
 EXTRA_DIST += riemann.proto
-if HAVE_PROTOC_C
+if BUILD_PLUGIN_WRITE_RIEMANN
 CLEANFILES += riemann.pb-c.c riemann.pb-c.h
 
 BUILT_SOURCES += riemann.pb-c.c riemann.pb-c.h