Fix print of extra 0 when floats have only zeroes as decimals (#26)

Fixes #25

Author: platisd

library.properties

@@ -1,5 +1,5 @@
 name=Nokia 5110 LCD library
-version=2.7.0
+version=2.7.1
 author=Dimitris Platis
 maintainer=Dimitris Platis <dimitris@plat.is>
 sentence=Arduino library for driving the Nokia 5110 LCD

src/Nokia_LCD.cpp

@@ -379,6 +379,10 @@ bool Nokia_LCD::print(double number, unsigned short decimals) {
         }
     }
 
+    if (fractional == 0) {
+        // If the fractional part is 0, then we have already printed it
+        return out_of_bounds;
+    }
     // prints the rest of the fractional
     return (out_of_bounds || print(fractional));
 }