AppVeyor: update to nasm 2.15.05.

Author: XhmikosR

.appveyor.yml

@@ -7,7 +7,7 @@ clone_depth: 5
 
 install: |
   git submodule update --init --recursive
-  set NASM_VER=2.14.02
+  set NASM_VER=2.15.05
   set NASM_FNAME_FULL=nasm-%NASM_VER%-win64
   set NASM_FNAME=nasm-%NASM_VER%
   set NASM_URL=https://www.nasm.us/pub/nasm/releasebuilds/%NASM_VER%/win64/%NASM_FNAME_FULL%.zip