Remove extra spaces in custom openSSL documentation. (pythonGH-93568)

(cherry picked from commit 4875433)

Co-authored-by: Xiao Chen <chenxiao_7@163.com>

Doc/using/unix.rst

@@ -158,16 +158,16 @@ Custom OpenSSL
    .. code-block:: shell-session
 
       $ curl -O https://www.openssl.org/source/openssl-VERSION.tar.gz
-         $ tar xzf openssl-VERSION
-         $ pushd openssl-VERSION
-         $ ./config \
-              --prefix=/usr/local/custom-openssl \
-              --libdir=lib \
-              --openssldir=/etc/ssl
-         $ make -j1 depend
-         $ make -j8
-         $ make install_sw
-         $ popd
+      $ tar xzf openssl-VERSION
+      $ pushd openssl-VERSION
+      $ ./config \
+          --prefix=/usr/local/custom-openssl \
+          --libdir=lib \
+          --openssldir=/etc/ssl
+      $ make -j1 depend
+      $ make -j8
+      $ make install_sw
+      $ popd
 
 3. Build Python with custom OpenSSL
    (see the configure `--with-openssl` and `--with-openssl-rpath` options)