small rename

Author: Alexander Perepelkin

src/Properties.cpp

@@ -135,9 +135,9 @@ namespace log4cpp {
  if (key == "${") {
  result += "${";
  } else {
- char* value = std::getenv(key.c_str());
- if (value) {
- result += value;
+ char* env_value = std::getenv(key.c_str());
+ if (env_value) {
+ result += env_value;
  } else {
  const_iterator it = find(key);
  if (it == end()) {