Fix Windows build

appveyor.yml

@@ -1,6 +1,6 @@
 environment:
   matrix:
-    - MSYS: C:/msys64/mingw32
+    - MSYSTEM: MINGW32
 
 branches:
   only:
@@ -11,10 +11,9 @@ clone_depth: 1
 # init:
 #   - ps: iex ((new-object net.webclient).DownloadString('https://raw.githubusercontent.com/appveyor/ci/master/scripts/enable-rdp.ps1'))
 
-install:
-
+build_script:
+  - C:\msys64\usr\bin\pacman -Syuu --needed --noconfirm --ask=127
   - ps: |
-        $env:MSYSTEM="MINGW32"
         $env:TIME_STRING=(get-date -UFormat "%Y-%m-%d").ToString()
         $env:BUILDROOT="C:\msys64\home\appveyor\gajim\win\_build_root"
 
@@ -23,14 +22,11 @@ install:
           C:\msys64\usr\bin\sh.exe --login -c $command
         }
 
-        bash 'pacman -Sy --noconfirm git'
         bash 'git clone C:/projects/gajim C:/msys64/home/appveyor/gajim'
         bash 'C:/msys64/home/appveyor/gajim/win/build.sh'
         Push-AppveyorArtifact "$($env:BUILDROOT)/Gajim.exe" -FileName "Gajim-Master-$($env:TIME_STRING).exe"
         Push-AppveyorArtifact "$($env:BUILDROOT)/Gajim-Portable.exe" -FileName "Gajim-Portable-Master-$($env:TIME_STRING).exe"
 
-build: off
-
 # on_finish:
 #   - ps: $blockRdp = $true; iex ((new-object net.webclient).DownloadString('https://raw.githubusercontent.com/appveyor/ci/master/scripts/enable-rdp.ps1'))
 

win/_base.sh

@@ -51,9 +51,8 @@ function build_compileall {
 }
 
 function install_pre_deps {
-    pacman -S --needed --noconfirm p7zip git \
-        mingw-w64-"${ARCH}"-nsis wget intltool mingw-w64-"${ARCH}"-toolchain \
-        mingw-w64-i686-python3
+    pacman -S --needed --noconfirm p7zip \
+        mingw-w64-"${ARCH}"-nsis wget intltool mingw-w64-"${ARCH}"-toolchain
 }
 
 function create_root {