Fix alignment padding checks in UndertaleIO

To check if pos is aligned we calculate (pos & (alignment - 1)).
When pos is aligned, the result will always be 0.
However right now the Align functions of UTReader/Writer
checks if it equals to the intended padding byte, which
makes zero sense. This commit makes them check against 0.

UndertaleModLib/UndertaleIO.cs

@@ -650,7 +650,7 @@ public void ToHere()
 
         public void Align(int alignment, byte paddingbyte = 0x00)
         {
-            while ((AbsPosition & (alignment - 1)) != paddingbyte)
+            while ((AbsPosition & (alignment - 1)) != 0)
             {
                 DebugUtil.Assert(ReadByte() == paddingbyte, "Invalid alignment padding");
             }
@@ -860,7 +860,7 @@ public void ThrowIfUnwrittenObjects()
 
         public void Align(int alignment, byte paddingbyte = 0x00)
         {
-            while ((Position & (alignment - 1)) != paddingbyte)
+            while ((Position & (alignment - 1)) != 0)
             {
                 Write(paddingbyte);
             }