script/build-git: try harder to fix Homebrew

For an unknown reason, sometimes libintl.h is missing on macOS when it
should not be.  Try harder to fix this by reinstalling the packages
which are already allegedly installed and forcing an unlink and re-link.

script/build-git

@@ -5,7 +5,12 @@ DIR="$1"
 case $(uname -s) in
   Darwin)
     brew install curl zlib pcre2 gettext openssl
-    brew link --force zlib pcre2 gettext openssl;;
+    brew reinstall curl zlib pcre2 gettext openssl
+    for i in curl zlib pcre2 gettext openssl
+    do
+      brew unlink $i || true;
+      brew link --force $i || true
+    done;;
   Linux)
     export DEBIAN_FRONTEND=noninteractive
     sed -e 's/^deb/deb-src/' /etc/apt/sources.list | sudo tee /etc/apt/sources.list.d/src.list