Remove unused LIBCURL_CPPFLAGS variable which should help cgminer compile on other platforms.

Makefile.am

@@ -29,7 +29,7 @@ cgminer_SOURCES	= elist.h miner.h compat.h bench_block.h	\
 
 cgminer_LDFLAGS	= $(PTHREAD_FLAGS)
 cgminer_LDADD	= @LIBCURL_LIBS@ @JANSSON_LIBS@ @PTHREAD_LIBS@ @OPENCL_LIBS@ @NCURSES_LIBS@ @PDCURSES_LIBS@ @WS2_LIBS@ lib/libgnu.a ccan/libccan.a
-cgminer_CPPFLAGS = @LIBCURL_CPPFLAGS@ -I$(top_builddir)/lib -I$(top_srcdir)/lib
+cgminer_CPPFLAGS = -I$(top_builddir)/lib -I$(top_srcdir)/lib
 
 if HAVE_x86_64
 if HAS_YASM

configure.ac

@@ -191,7 +191,6 @@ PKG_PROG_PKG_CONFIG()
 
 PKG_CHECK_MODULES([LIBCURL], [libcurl >= 7.15.6], [AC_DEFINE([CURL_HAS_SOCKOPT], [1], [Defined if version of curl supports sockopts.])],
 [PKG_CHECK_MODULES([LIBCURL], [libcurl >= 7.10.1], ,[AC_MSG_ERROR([Missing required libcurl dev >= 7.10.1])])])
-AC_SUBST(LIBCURL_CPPFLAGS)
 AC_SUBST(LIBCURL_LIBS)
 
 dnl CCAN wants to know a lot of vars.