s2opc: make ready for llvm 21 (#13926)

Ref: #13915

---------

Signed-off-by: David Korczynski <[email protected]>

Author: DavidKorczynski

projects/s2opc/build.sh

@@ -16,13 +16,16 @@
 #
 ################################################################################
 
+if [ -f /usr/local/bin/clang-21 ]; then
+  export CFLAGS="${CFLAGS} -Wno-error=unterminated-string-initialization"
+fi
+
 MBEDTLS_BUILD=$WORK/mbedtls
 EXPAT_BUILD=$WORK/expat
 S2OPC_BUILD=$WORK/s2opc
 SAMPLES=$SRC/S2OPC-fuzzing-data
 
 # Build the dependencies
-
 ## Configure mbedtls to disable support of the AES-NI instructions, known to cause error with some sanitizers
 tar xjf $SRC/mbedtls.tbz2 -C $WORK
 sed 's,#define MBEDTLS_AESNI_C,//#define MBEDTLS_AESNI_C,' -i $WORK/mbedtls-2.*/include/mbedtls/config.h