Uninitialized variable use in nextKeyIdx LatexInfo::dispatch

[Stephan Witt]

Hi Kornel,

Apple clang has spotted a problem probably introduced in change 74c849d651.

====
src/lyxfind.cpp:1672:10: warning: variable 'nextKeyIdx' is used uninitialized 
whenever switch case is taken
      [-Wsometimes-uninitialized]
    case KeyInfo::isMain: {
         ^~~~~~~~~~~~~~~
src/lyxfind.cpp:1695:10: note: uninitialized use occurs here
  return(nextKeyIdx);
         ^~~~~~~~~~
src/lyxfind.cpp:1592:17: note: initialize the variable 'nextKeyIdx' to silence 
this warning
  int nextKeyIdx;
                ^
                 = 0
====

Can you verify what should be done here, please?

Stephan