libproxy: Remove PIE flags from SECURITY_PIE_CFLAGS
External compilers will explicitly pass -fPIE -pie flags
unlike internal toolchain which does not use them, so the build
fails with external toolchains because, its passing these
flags to linker when building shared library, which is not
correct it should just use -fPIC
Fixes errors e.g.
| /mnt/a/oe/build/tmp/work/corei7-64-bec-linux/libproxy/0.4.14-r0/recipe-sysroot-native/usr/bin/x86_64-bec-linux/x86_64-bec-linux-ld: ../libmodman/libmodman.a(module_manager.cpp.o): relocation R_X86_64_PC32 against symbol `_ZNSt8_Rb_treeINSt7__cxx1112basic_stringIcSt11char_traitsIcESaIcEEESt4pairIKS5_St6vectorIPN9libmodman14base_extensionESaISB_EEESt10_Select1stISE_ESt4lessIS5_ESaISE_EE8_M_eraseEPSt13_Rb_tree_nodeISE_E' can not be used when making a shared object; recompile with -fPIC
Signed-off-by: Khem Raj <raj.khem@gmail.com> Signed-off-by: Ross Burton <ross.burton@intel.com>
