Revert "change buildscript to use github mirror"

This reverts commit 4c7781e1.
Seems to exhibit weird encoding failures on maxima 5.41

buildscript.sh

@@ -7,9 +7,10 @@ echo ${MAXIMA_VERSION?Error \$MAXIMA_VERSION is not defined} \
      ${SBCL_VERSION?Error \$SBCL_VERSION is not defined}
 
 apt-get update
-apt-get install -y bzip2 make wget python3 gcc texinfo curl libcap2-bin git autoconf
+apt-get install -y bzip2 make wget python3 gcc texinfo curl libcap2-bin
 
 mkdir -p ${SRC}
+wget "https://sourceforge.net/projects/maxima/files/Maxima-source/${MAXIMA_VERSION}-source/maxima-${MAXIMA_VERSION}.tar.gz" -O "${SRC}/maxima-${MAXIMA_VERSION}.tar.gz"
 wget "https://github.com/sbcl/sbcl/archive/refs/tags/sbcl-${SBCL_VERSION}.tar.gz" -O "${SRC}/sbcl-${SBCL_VERSION}.tar.gz"
 
 # Compile sbcl (installs and removes debian sbcl for bootstrapping)
@@ -23,11 +24,11 @@ echo "\"$SBCL_VERSION\"" > version.lisp-expr
 apt remove -y sbcl
 ./install.sh
 
-cd ${SRC}
-git clone --depth 1 --branch "$MAXIMA_VERSION" "https://github.com/mathinstitut/maxima-mirror" maxima
 # Compile maxima
-cd maxima
-autoreconf -i
+cd ${SRC}
+tar -xf maxima-${MAXIMA_VERSION}.tar.gz
+rm maxima-${MAXIMA_VERSION}.tar.gz
+cd maxima-${MAXIMA_VERSION}
 ./configure
 make
 make install
@@ -42,5 +43,5 @@ gcc -shared maxima_fork.c -lbsd -fPIC -Wall -Wextra -DN_SLOT="${MAX_USER}" -o li
 mv libmaximafork.so /usr/lib
 rm -r ${SRC} /maxima_fork.c
 mkdir -p ${LIB} ${LOG} ${TMP} ${PLOT} ${ASSETS} ${BIN}
-apt-get purge -y bzip2 make wget python3 gcc texinfo libcap2-bin git autoconf
+apt-get purge -y bzip2 make wget python3 gcc texinfo
 apt-get autoremove -y