Compiling with -Werror=pendantic produces an error (closes #183)

src/modbus.h

@@ -176,7 +176,7 @@ typedef enum
 {
     MODBUS_ERROR_RECOVERY_NONE          = 0,
     MODBUS_ERROR_RECOVERY_LINK          = (1<<1),
-    MODBUS_ERROR_RECOVERY_PROTOCOL      = (1<<2),
+    MODBUS_ERROR_RECOVERY_PROTOCOL      = (1<<2)
 } modbus_error_recovery_mode;
 
 MODBUS_API int modbus_set_slave(modbus_t* ctx, int slave);