remove filtering cflags in configure and respect userflags
--- a/Makefile.in
+++ b/Makefile.in
@@ -1,6 +1,4 @@
 CC ?= %CC%
-CFLAGS += -O2 -U_FORTIFY_SOURCE -D_FORTIFY_SOURCE=2 -I/usr/local/include %CFLAGS% $(RPM_OPT_FLAGS)
-LDFLAGS += -L/usr/local/lib
 LDLIBS += %LDLIBS% %PTHREAD%
 
 BINARIES = ttyrec ttyplay ttytime
--- a/configure
+++ b/configure
@@ -237,27 +237,8 @@ EOF
     fi
 fi
 
-echo "Checking for supported compiler options..."
-for w in -Wall -Wextra -pedantic -Wno-unused-result -Wbad-function-cast -Wmissing-declarations \
-    -Wmissing-prototypes -Wnested-externs -Wold-style-definition -Wstrict-prototypes \
-    -Wpointer-sign -Wmissing-parameter-type -Wold-style-declaration -Wl,--as-needed \
-    -Wno-unused-command-line-argument
-do
-    echo 'int main(void) { return 0; }' >"$srcfile.c"
-    if [ "$($CC "$srcfile.c" $w -o /dev/null 2>&1 | wc -l)" = 0 ]; then
-        echo "... OK $w"
-        if echo "$w" | grep -q -- '-Wl,'; then
-            LDFLAGS="$LDFLAGS $w"
-        else
-            CFLAGS="$CFLAGS $w"
-        fi
-    else
-        echo "... unsupported $w"
-    fi
-done
-
 cat "$(dirname "$0")"/Makefile.in > "$(dirname "$0")"/Makefile.tmp
-for i in CC LDLIBS CFLAGS COMPRESS_ZSTD PTHREAD
+for i in CC LDLIBS COMPRESS_ZSTD PTHREAD
 do
     replace=$(eval printf "%b" "\"\$$i\"")
     sed "s:%$i%:$replace:g" "$(dirname "$0")"/Makefile.tmp > "$(dirname "$0")"/Makefile