Fix setenv action to strdup key=variable

Author: Felipe Zimmerle

CHANGES

@@ -1,6 +1,8 @@
 v3.0.4 - YYYY-MMM-DD (to be released)
 -------------------------------------
 
+ - Fix setenv action to strdup key=variable
+   [@zimmerle]
  - Allow 0 length JSON requests.
    [Issue #1822 - @allanbomsft, @zimmerle, @victorhora, @marcstern]
  - Fix "make dist" target to include default configuration

src/actions/set_env.cc

@@ -37,7 +37,7 @@ bool SetENV::evaluate(Rule *rule, Transaction *t) {
     ms_dbg_a(t, 8, "Setting envoriment variable: "
         + colNameExpanded + ".");
 
-    putenv((char *)colNameExpanded.c_str());
+    putenv(strdup(colNameExpanded.c_str()));
 
     return true;
 }