Optimized/modernized remove_ctrl_a() a little.

src/sbbs3/str.cpp

@@ -47,14 +47,14 @@ const char *mon[]={"Jan","Feb","Mar","Apr","May","Jun"
 char* DLLCALL remove_ctrl_a(char *instr, char *outstr)
 {
 	char str[1024],*p;
-	uint i,j,k;
+	uint i,j;
 
-	j=strlen(instr);
-	for(k=i=0;i<j;i++) {
+	for(i=j=0;instr[i];i++) {
 		if(instr[i]==CTRL_A)
 			i++;
-		else str[k++]=instr[i]; }
-	str[k]=0;
+		else str[j++]=instr[i]; 
+	}
+	str[j]=0;
 	if(outstr!=NULL)
 		p=outstr;
 	else