Configuration: Fix const and signedness compile warnings

Change-Id: I701559814b2aee6f84f10e612f128da40f6a51c1
diff --git a/CommonLibs/Configuration.cpp b/CommonLibs/Configuration.cpp
index bfff893..7ca193b 100644
--- a/CommonLibs/Configuration.cpp
+++ b/CommonLibs/Configuration.cpp
@@ -56,7 +56,7 @@
 static std::string replaceAll(const std::string input, const std::string search, const std::string replace)
 {
 	std::string output = input;
- 	int index = 0;
+	size_t index = 0;
 
 	while (true) {
 		index = output.find(search, index);