Add missing semicolon in backtrace debug code.

Apparently backtrace has not been used for debugging since it was broken in 7fba1f0.

Even though this is test code it might be good to find a way to test it to prevent regressions.

src/common/stackTrace.c

@@ -52,7 +52,7 @@ static struct StackTraceLocal
 static struct StackTraceBackLocal
 {
     struct backtrace_state *backTraceState;                         // Backtrace state struct
-} stackTraceBackLocal
+} stackTraceBackLocal;
 
 void
 stackTraceInit(const char *exe)