Put the abbreviated commit hash in the EXENAME for AppVeyor

srb2win-master-a6d49eaaa.exe

(cherry picked from commit d3315ae03c57296bfb5a7f9f5959492bdb7de24c)

appveyor.yml

@@ -83,7 +83,9 @@ before_build:
 - ccache -V
 - ccache -s
 - if [%NOUPX%] == [1] ( set "NOUPX=NOUPX=1" ) else ( set "NOUPX=" )
-- set "EXENAME=EXENAME=srb2win-%APPVEYOR_REPO_BRANCH%-%APPVEYOR_REPO_COMMIT%.exe"
+# get abbreviated (7 char) commit hash
+- set "COMMIT=%APPVEYOR_REPO_COMMIT:~0,7%"
+- set "EXENAME=EXENAME=srb2win-%APPVEYOR_REPO_BRANCH%-%COMMIT%.exe"
 - set "SRB2_MFLAGS=-C src WARNINGMODE=1 CCACHE=1 NOOBJDUMP=1 %NOUPX% %EXENAME%"
 - if [%X86_64%] == [1] ( set "MINGW_FLAGS=MINGW64=1 X86_64=1 GCC81=1" ) else ( set "MINGW_FLAGS=MINGW=1 GCC91=1" )
 - set "SRB2_MFLAGS=%SRB2_MFLAGS% %MINGW_FLAGS% %CONFIGURATION%=1"