Fixed bug

There was a potential bug when stripping blanks from short strings (1 char)

src/tools/Tools.cpp

@@ -283,7 +283,7 @@ vector<string> Tools::ls(const string&d){
 void Tools::stripLeadingAndTrailingBlanks( std::string& str ){
   std::size_t first=str.find_first_not_of(' ');
   std::size_t last=str.find_last_not_of(' ');
-  if( first<last ) str=str.substr(first,last+1);
+  if( first<=last && first!=std::string::npos) str=str.substr(first,last+1);
 }
 
 std::string Tools::extension(const std::string&s){