Fix smeltery overfilling if it was empty and one block could overfill…

… it. (I'm looking at you there, compressed cobble)

src/main/java/tconstruct/smeltery/logic/SmelteryLogic.java

@@ -507,8 +507,12 @@ boolean addMoltenMetal (FluidStack liquid, boolean first)
         needsUpdate = true;
         if (moltenMetal.size() == 0)
         {
+            // does it fit in?
+            if(liquid.amount > this.getCapacity())
+                return false;
+
             moltenMetal.add(liquid.copy());
-            currentLiquid += liquid.amount;
+            updateCurrentLiquid();
             return true;
         }
         else