don't hardcode -fstack-protector-strong in configure.ac/gbuild. We get the
hardening flags from dpkg-buildflags anyway.

diff --git a/solenv/gbuild/platform/com_GCC_defs.mk b/solenv/gbuild/platform/com_GCC_defs.mk
index 712a61df544f..0d50f538ba7b 100644
--- a/solenv/gbuild/platform/com_GCC_defs.mk
+++ b/solenv/gbuild/platform/com_GCC_defs.mk
@@ -67,7 +67,6 @@ gb_CFLAGS_COMMON := \
 	-fmessage-length=0 \
 	-fno-common \
 	-pipe \
-	-fstack-protector-strong \
 	$(if $(gb_COLOR),-fdiagnostics-color=always) \
 
 gb_CXXFLAGS_COMMON := \
@@ -82,7 +81,6 @@ gb_CXXFLAGS_COMMON := \
 	-fmessage-length=0 \
 	-fno-common \
 	-pipe \
-	-fstack-protector-strong \
 	$(if $(gb_COLOR),-fdiagnostics-color=always) \
 
 ifeq ($(HAVE_WDEPRECATED_COPY_DTOR),TRUE)
@@ -136,8 +134,6 @@ endif
 gb_VISIBILITY_FLAGS_CXX := -fvisibility-inlines-hidden
 gb_CXXFLAGS_COMMON += $(gb_VISIBILITY_FLAGS_CXX)
 
-gb_LinkTarget_LDFLAGS += -fstack-protector-strong
-
 ifneq ($(gb_ENABLE_PCH),)
 ifeq ($(COM_IS_CLANG),TRUE)
 # Clang by default includes in the PCH timestamps of the files it was