Fix duplicated symbols
Fix duplicated symbols caused by having definition instead of declaration in
header file.
diff --git a/src/php/ext/grpc/server.c b/src/php/ext/grpc/server.c
index 00d08c6..a5cfd95 100644
--- a/src/php/ext/grpc/server.c
+++ b/src/php/ext/grpc/server.c
@@ -56,6 +56,8 @@
#include "channel.h"
#include "server_credentials.h"
+zend_class_entry *grpc_ce_server;
+
/* Frees and destroys an instance of wrapped_grpc_server */
void free_wrapped_grpc_server(void *object TSRMLS_DC) {
wrapped_grpc_server *server = (wrapped_grpc_server *)object;