Fix build failure when using Swig 4.

Taken from upstream:
https://github.com/fifengine/fifengine/commit/d14f232f4cd9a00b05d6872957070e8c020f515d

diff --git a/CMakeLists.txt b/CMakeLists.txt
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -893,7 +893,7 @@ if(build-python)
   find_package(PythonLibs ${PYTHON_VERSION_STRING} EXACT)
   include_directories(${PYTHON_INCLUDE_PATH})
 
-  set(CMAKE_SWIG_FLAGS -modern -fastdispatch -dirvtable -nosafecstrings -noproxydel -fastproxy -fastinit -fastunpack -fastquery -modernargs -nobuildnone -keyword -w511 -w473 -w404 -w314)
+  set(CMAKE_SWIG_FLAGS -modern -fastdispatch -dirvtable -noproxydel -fastproxy -fastinit -fastunpack -fastquery -modernargs -keyword -w511 -w473 -w404 -w314)
 
   set_source_files_properties("${PROJECT_BINARY_DIR}/fife.i" PROPERTIES CPLUSPLUS ON)
   set(FIFE_SOURCES ${FIFE_CORE_SRC})
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<tr><td><span title='2021-12-18 04:09:47 +0100'>2021-12-18</span></td><td><a href='/guix/commit/tests/cran.scm?id=10ceb3e84654e024f14a4b048e7d68492ed9dc7c'>import: cran: Fix description-&gt;package test.</a><span class='msg-avail'>...<span class='msg-tooltip'>This follows up on commit 5cd1019488c44081aaf030fbe8bc357d78daef23.

* tests/cran.scm (description): Include a very long line.
(description-&gt;package): Update the golden description to match the
paragraph filling now performed by BEAUTIFY-DESCRIPTION.
</span></span></td><td>Tobias Geerinckx-Rice</td></tr>
<tr><td><span title='2021-07-11 00:49:16 +0200'>2021-07-11</span></td><td><a href='/guix/commit/tests/cran.scm?id=aa6921634b4ea9988af0e37bfbb56780c431ef64'>import: cran: Emit new-style package inputs.</a><span class='msg-avail'>...<span class='msg-tooltip'>* guix/import/cran.scm (format-inputs): Emit symbols or
'specification-&gt;package' calls.
(maybe-inputs): Wrap in 'list' instead of 'quasiquote'.
* tests/cran.scm ("description-&gt;package"): Adjust accordingly.
</span></span></td><td>Ludovic Courtès</td></tr>
<tr><td><span title='2020-01-16 23:14:05 +0100'>2020-01-16</span></td><td><a href='/guix/commit/tests/cran.scm?id=cfd1ed84013df85f0e473884ef4038b4bd7120d4'>import: cran: Avoid uses of '@@' in the tests.</a><span class='msg-avail'>...<span class='msg-tooltip'>* guix/import/cran.scm (description-&gt;alist, description-&gt;package): Export.
&lt;top level&gt;: Set! 'listify'.
* tests/cran.scm (description-alist, "description-&gt;package"): Remove use
of '@@' to access the relevant bindings.
</span></span></td><td>Ludovic Courtès</td></tr>