- Don't do bash pattern substitutions

Index: configure.ac
--- configure.ac.orig
+++ configure.ac
@@ -984,12 +984,12 @@ AS_CASE([$enable_maintainer_flags],
 )
 
 # strip leading spaces
-MAINTAINER_CFLAGS=${MAINTAINER_CFLAGS#*  }
+MAINTAINER_CFLAGS=`echo ${MAINTAINER_CFLAGS} | sed 's,^[ \t]*,,g'`
 AC_SUBST(MAINTAINER_CFLAGS)
 
 dnl === Dependencies, compiler flags and linker libraries =====================
 # strip leading space
-BACKEND_PC_FILES=${BACKEND_PC_FILES#* }
+BACKEND_PC_FILES=`echo ${BACKEND_PC_FILES} | sed 's,^[ \t]*,,g'`
 
 # public dependencies, will fill the Requires: field of clutter.pc
 CLUTTER_REQUIRES="$CLUTTER_BASE_PC_FILES $BACKEND_PC_FILES"
