Fix to support formatting chars { or } when no args passed to log functions

include/spdlog/details/line_logger.h

@@ -85,6 +85,13 @@ public:
         }
     }
 
+
+    void write(const char* what)
+    {
+        if (_enabled)
+            _log_msg.raw << what;
+    }
+
     template<typename T>
     line_logger& operator<<(const T& what)
     {