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='2021-07-20 23:43:29 +0200'>2021-07-20</span></td><td><a href='/guix/commit/tests/hackage.scm?id=81a87222a1c26fca9fd642213129184ea0fb5185'>import: hackage: Emit new-style package inputs.</a><span class='msg-avail'>...<span class='msg-tooltip'>* guix/import/hackage.scm (hackage-module-&gt;sexp)[dependencies]
[native-dependencies]: Make into a list of symbols.
[maybe-inputs]: Wrap INPUTS in 'list' instead of 'quasiquote'.
* tests/hackage.scm (match-ghc-foo)
(match-ghc-foo-6)
(match-ghc-foo-revision)
(match-ghc-foo-import): Adjust accordingly.

Signed-off-by: Ludovic Courtès &lt;ludo@gnu.org&gt;
</span></span></td><td>Sarah Morgensen</td></tr>
<tr><td><span title='2021-06-25 15:12:05 +0200'>2021-06-25</span></td><td><a href='/guix/commit/tests/hackage.scm?id=dfac3e643a924ccefc997b4433a0b5c35928d657'>import: hackage: Support "common" field and imports</a><span class='msg-avail'>...<span class='msg-tooltip'>Fixes &lt;https://issues.guix.gnu.org/48701&gt;.

* guix/import/cabal.scm (make-cabal-parser): Modify.
(is-common): New variable.
(lex-common): New procedure.
(is-id): Modify.
(eval-cabal): Modify.
* tests/hackage.scm ("hackage-&gt;guix-package test cabal import") New test.

Signed-off-by: Ludovic Courtès &lt;ludo@gnu.org&gt;
</span></span></td><td>Philip Munksgaard</td></tr>
<tr><td><span title='2021-05-22 23:39:27 +0200'>2021-05-22</span></td><td><a href='/guix/commit/tests/hackage.scm?id=cfec09a9928e171a724f630ba652ea0241d52e92'>import: hackage: Prefix licenses with 'license:'.</a><span class='msg-avail'>...<span class='msg-tooltip'>* guix/import/hackage.scm (string-&gt;license): Prefix the value of the license
field with ‘license:’.
* tests/hackage.scm (match-ghc-foo, match-ghc-foo-6, match-ghc-foo-revision):
Adjust accordingly.

Signed-off-by: Ludovic Courtès &lt;ludo@gnu.org&gt;
</span></span></td><td>Xinglu Chen</td></tr>