Temporarily change O2_DISABLE_FPE_TRAP to O2_ENABLE_FPE_TRAP

Given that there are potentially many places producing FPE if with FPE trapping enbaled,
in order to merge this PR changing default to NOT enable trapping with possibility
to enable it via env.var O2_ENABLE_FPE_TRAP with bits corresponding to enabled FEs:
FE_INVALID(=8)|FE_DIVBYZERO(=4)|FE_OVERFLOW(=1)

Author: shahor02

Common/Utils/src/fpu.cxx

@@ -33,8 +33,10 @@ static void __attribute__((constructor)) trapfpe()
 {
   // allows to disable set of particular FE's by setting corresponding bit of the O2_DISABLE_FPE_TRAP,
   // i.e. to enable only FE_DIVBYZERO use O2_DISABLE_FPE_TRAP=9
-  const char* ev = std::getenv("O2_DISABLE_FPE_TRAP");
-  int enabledFE = (FE_INVALID | FE_DIVBYZERO | FE_OVERFLOW) & ~(ev ? atoi(ev) : 0);
+  //  const char* ev = std::getenv("O2_DISABLE_FPE_TRAP");
+  //  int enabledFE = (FE_INVALID | FE_DIVBYZERO | FE_OVERFLOW) & ~(ev ? atoi(ev) : 0);
+  const char* ev = std::getenv("O2_ENABLE_FPE_TRAP");
+  int enabledFE = (FE_INVALID | FE_DIVBYZERO | FE_OVERFLOW) & (ev ? atoi(ev) : 0);
   if (enabledFE) {
     feenableexcept(enabledFE);
   }