snmp: fix include statement by removing trailing backslash

Author: k402xxxcenxxx

plugins/in_snmp/in_snmp.c

@@ -2,7 +2,7 @@
 #include <stdlib.h>
 #include <string.h>
 #include <net-snmp/net-snmp-config.h>
-#include <net-snmp/net-snmp-includes.h>\
+#include <net-snmp/net-snmp-includes.h>
 #include <msgpack.h>
 #include <fluent-bit/flb_input.h>
 #include <fluent-bit/flb_time.h>