fdo#52275: Revert "mysqlcppconn: work around weird gcc issue"

This reverts commit d3d533c9.

Hard-coding -std=c++xy in one module is a bad idea.

None of these gccs give any spurious error in gnu++11 mode now:
gcc (GCC) 4.6.3 20120306 (Red Hat 4.6.3-2)
gcc (GCC) 4.7.0 20120507 (Red Hat 4.7.0-5)

mysqlcppconn/mysql_config.pmk

@@ -47,9 +47,3 @@ CFLAGS+=-DCPPDBC_WIN32 -D_CRT_SECURE_NO_WARNINGS -D_SCL_SECURE_NO_WARNINGS
 
 CFLAGS+=-I$(PRJINC) -I$(PRJINC)$/cppconn $(MYSQL_INC) -DCPPCONN_LIB_BUILD
 
-# workaround for gcc bug (4.6.1 20110908):
-# it complains about std::basic string operator= overloading ambiguity
-.IF "$(COM)"=="GCC"
-CFLAGSCXX+=-std=c++98
-.ENDIF # "$(COM)"=="GCC"
-