Avoid potential format-error and set watchdog

Author: Gemba

skyscraper.pro

@@ -16,6 +16,10 @@ unix {
   }
 }
 
+*-g++* {
+    QMAKE_CXXFLAGS += -Werror=format-security
+}
+
 # Installation prefix path for bin/Skyscraper and etc/skyscraper/*
 PREFIX=$$(PREFIX)
 # One time set with "PREFIX=/path/to qmake"?

src/nocolor.cpp

@@ -84,7 +84,7 @@ void printVA(int nvargs, const char *fmt, ...) {
                 }
             }
         }
-        printf(fmtPlain.toStdString().c_str());
+        printf("%s", fmtPlain.toStdString().c_str());
     } else {
         va_start(args, fmt);
         vprintf(fmt, args);