pgsql: Remove redeclaration of struct sqlca_t --- unnecessary and

Log Message:
-----------
Remove redeclaration of struct sqlca_t --- unnecessary and provokes
warnings on some compilers.

Modified Files:
--------------
pgsql/src/interfaces/ecpg/include:
ecpglib.h (r1.68 -> r1.69)
(http://developer.postgresql.org/cvsweb.cgi/pgsql/src/interfaces/ecpg/include/ecpglib.h.diff?r1=1.68&r2=1.69)