Address fatal compiler warning.

Newer IDF toolchain is stricter, and we'd apparently failed to build test
the Lua-5.1 path for some time.

components/lua/lua-5.1/ldump.c

@@ -178,7 +178,7 @@ static void DumpCode(const Proto *f, DumpState* D)
 
 static void DumpString(const TString* s, DumpState* D)
 {
- if (s==NULL || getstr(s)==NULL)
+ if (s==NULL)
  {
   strsize_t size=0;
   DumpSize(size,D);