Merge pull request #5815 from roncapat/master

Change double quotes to single quotes

cores/arduino/Print.cpp

@@ -250,7 +250,7 @@ size_t Print::printFloat(double number, uint8_t digits)
 
   // Print the decimal point, but only if there are digits beyond
   if (digits > 0) {
-    n += print("."); 
+    n += print('.'); 
   }
 
   // Extract digits from the remainder one at a time