Bug 798802 - Online Price quote - Stocks not working GNU 5.0 Windows

Change the property-tree path delimiter for constructing paths from
'.' that's commonly used in stock symbols, to '|' that isn't.

libgnucash/app-utils/gnc-quotes.cpp

@@ -479,8 +479,9 @@ GncQuotesImpl::query_fq (const char* source, const StrVec& commodities)
                   commodities.cend(),
                   [source, &pt](auto sym)
                       {
-                          std::string key{source};
-                          key += "." + sym;
+                          using Path = bpt::ptree::path_type;
+                          Path key{source, '|'};
+                          key /= Path{sym, '|'};
                           pt.put(key, "");
                       });
     std::ostringstream result;